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PCP-ATOP(1) General Commands Manual PCP-ATOP(1)
pcp-atop - Advanced System and Process Monitor
Interactive Usage:
pcp [pcp options] atop [-aABcCdDfFgGHmMnNopRsuvxyY1] [-L linelen]
[-Plabel[,label]... [-Z]] [interval [samples]]
Writing and reading PCP archive folios:
pcp [pcp options] atop -w folio [-a] [-S] [interval [samples]]
pcp [pcp options] atop -r folio [-AcCdDfFgGmMnNopRsuvxy1] [-b [yy-
mm-dd] hh:mm] [-e yy-mm-dd] hh:mm] [-L linelen]
[-Plabel[,label]... [-Z]] [interval [samples]]
The program pcp-atop is an interactive monitor to view various
aspects of load on a system. Every interval seconds (default: 10
seconds) information is gathered about the resource occupation on
system level of the most critical hardware resources (from a
performance point of view), i.e. CPUs, memory, disks and network
interfaces. Besides, information is gathered about the processes
(or threads) that are responsible for the utilization of the CPUs,
memory and disks. Network load per process is shown only when the
optional pmdabpf(1) or pmdabcc(1) metrics have been installed and
configured.
When running pcp-atop you can choose to view the system load in
bar graph mode or in text mode. In bar graph mode the resource
utilization of CPUs, memory, disks and network interfaces is shown
via (character-based) bar graphs, but only on system level. When
you want to view more detailed information on system level or when
you want to view the resource consumption on process or thread
level, you can switch to text mode by pressing the 'B' key.
Alternatively, you can use the 'B' key (again) to switch from text
mode to bar graph mode.
By default, pcp-atop starts in text mode unless the -B flag is
used or unless 'B' has been configured as a default flag in the
.atoprc file (for further information about default flags, refer
to the pcp-atoprc(5) man page).
In bar graph mode the terminal will be subdivided into four
character-based windows, i.e. one window for each hardware
resource:
Processors
The first bar shows the average busy percentage of all CPUs
with the bar label 'Avg' (might be abbreviated to 'Av' or
even just 'A'). The subsequent bars show the busy
percentages of single CPUs.
When there is not enough horizontal space to show all CPUs,
only the most busy CPUs per sample will be shown after the
width of each bar has been reduced to a minimum.
By default, the categories of CPU consumption are shown by
different colors in the bars, marked with a character 'S'
(system mode), 'U' (user mode), 'I' (interrupt handling), 's'
(steal) and 'G' (guest, i.e. consumed by virtual machines).
The top of the bar might consist of an unmarked color
representing a 'neutral' category. Suppose that the scale
unit is 5% per line and the total busy percentage is 54%
consisting of two categories of 27%. The two categories will
be rounded to 25% (5 lines of 5% each) but the total busy
percentage will be rounded to 55% (11 lines of 5%). Then the
top line will represent a 'neutral' category.
By pressing the 'H' key or by starting pcp-atop with the -H
flag, no categories are shown.
A red line is drawn in the bar graph as critical threshold.
By default this value is 90% and can be modified by the
'cpucritperc' option in the configuration file (see separate
pcp-atoprc(5) man page). When this value is set to zero, no
threshold line will be drawn.
Memory and swap space
Memory is presented as a column in which the specific
categories of memory consumption are shown. These categories
are (code, data and stack of) processes/kernel, slab caches
(i.e. dynamically allocated kernel memory), shared memory,
tmpfs, static huge pages, page cache and free memory.
Swap space (if present) is also presented as a column in
which the categories processes/tmpfs, shared memory and free
space are shown.
At the right side memory-related event counters are shown.
The bottom three counters are colored green when there is no
memory pressure. When considerable activity is noticed such
counter might be colored orange and with high activity red.
When memory pressure starts, usually memory page scanning
will be activated first. When pressure increases, memory
pages of processes might be swapped out to swap space (if
present).
The 'oomkills' counter (Out Of Memory killing) is most
serious: it reflects the number of processes that are killed
due to lack of memory (and swap). Therefore this counter
shows the absolute number (not per second) of processes being
killed during the last interval and will immediately be
colored red when it is 1 or more. Besides, after pcp-atop
has noticed OOM killing the 'oomkills' counter remains orange
for the next 15 minutes, just in case that you have missed
the OOM killing event itself.
When there is enough vertical space in the memory window,
event counters are shown about the number of memory pages
being swapped in, the number of memory pages paged out to
block devices and the number of memory pages paged in from
block devices.
Memory and swap space consumption will preferably be shown in
a character-based window that vertically uses the entire
screen for optimal granularity. However, when there are a lot
of disks and/or network interfaces the memory and swap space
consumption will be shown in a character-based window that
only uses the upper half of the screen.
Disks
For each disk the busy percentage is shown as a bar.
When there is not enough horizontal space to show all disks,
only the most busy disks per sample will be shown.
By default, categories of disk consumption are shown by
different colors in the bars, marked with a character 'R'
(read) and 'W' (write).
The top of the bar might consist of an unmarked color
representing a 'neutral' category. Suppose that the scale
unit is 5% per line and the total busy percentage is 54%
consisting of two categories of 27%. The two categories will
be rounded to 25% (5 lines of 5% each) but the total busy
percentage will be rounded to 55% (11 lines of 5%). Then the
top line will represent a 'neutral' category.
By pressing the 'H' key or by starting pcp-atop with the -H
flag, no categories are shown.
A red line is drawn in the bar graph as critical threshold.
By default this value is 90% and can be modified by the
'dskcritperc' option in the configuration file (see separate
atoprc man page). When this value is set to zero, no
threshold line will be drawn.
Interfaces
For each non-virtual network interface a double bar graph is
shown with a dedicated scale that reflects the traffic rate.
One of the bars shows the transmit rate ('TX') and the other
bar the receive rate ('RX'). The traffic scale of each
network interface remains at its highest level. All
interface scales can be reset during the measurement by
pressing the 'L' key.
Most often the real speed (maximum bandwidth) of network
interfaces is not known, e.g. in case of the network
interfaces of virtual machines. Therefore it is not possible
to show the interface utilization as a percentage. However,
when the real speed of an interface is known it will be shown
underneath the concerning bar graph.
When there is not enough horizontal space to show all network
interfaces, only the most busy interfaces per sample will be
shown.
Usually the bar graphs will not be sorted on busy percentage when
there is enough horizontal space. However, after switching from
text mode to bar graph mode the bar graphs might have been sorted
because this was needed for the presentation in text mode. The
next interval in bar graph mode shows the bars unsorted again
unless the window width is insufficient for all bars.
The remaining part of this manual page mainly describes the
information shown in text mode. When certain descriptions also
apply to bar graph mode it will be mentioned explicitly.
The initial screen in text mode shows if pcp-atop runs with
restricted view (unprivileged user) or unrestricted view
(privileged user). In case of restricted view pcp-atop does not
have the privileges (root identity or necessary capabilities) to
retrieve all counter values on system level and on process level.
does not have the privileges (no root identity nor the necessary
capabilities) to retrieve all counter values on system level and
on process level.
With every interval information is shown about the resource
occupation on system level (CPU, memory, disks and network
layers), followed by a list of processes which have been active
during the last interval. Notice that all processes that were
unchanged during the last interval re not shown, unless the key
'a' has been pressed or unless sorting on memory occupation is
done (then inactive processes are relevant as well). If the list
of active processes does not entirely fit on the screen, only the
top of the list is shown (sorted in order of activity).
The intervals are repeated till the number of samples (specified
as command argument) is reached, or till the key 'q' is pressed in
interactive mode.
When invoked via the pcp(1) command, the PCPIntro(1) options
-A/--align, -a/--archive, -h/--host, -O/--origin, -S/--start,
-s/--samples, -T/--finish, -t/--interval, -v/--version,
-z/--hostzone and -z/--timezone become indirectly available.
Additionally, the --hotproc option can be used to request the per-
process PCP metrics be used instead of the default proc metrics
from pmdaproc(1).
When pcp-atop is started, it checks whether the standard output
channel is connected to a screen, or to a file/pipe. In the first
case it produces screen control codes (via the ncurses library)
and behaves interactively; in the second case it produces flat
text output.
In interactive mode, the output of pcp-atop scales dynamically to
the current dimensions of the screen/window.
If the window is resized horizontally, columns will be added or
removed automatically. For this purpose, every column has a par‐
ticular weight. The columns with the highest weights that fit
within the current width will be shown.
If the window is resized vertically, lines of the process/thread
list will be added or removed automatically.
In interactive mode the output of pcp-atop can be controlled by
pressing particular keys. However it is also possible to specify
such key as flag on the command line. In that case pcp-atop
switches to the indicated mode on beforehand. This mode can be
modified again interactively. Specifying such key as flag is es‐
pecially useful when running pcp-atop with output to a pipe or
file (non-interactively). These flags are the same as the keys
that can be pressed in interactive mode (see section INTERACTIVE
COMMANDS).
Additional flags are available to support storage of pcp-atop data
in PCP archive format (see section PCP DATA STORAGE).
For the resource consumption on system level, pcp-atop uses colors
in text mode to indicate that a critical occupation percentage has
been (almost) reached. A critical occupation percentage means
that is likely that this load causes a noticeable negative perfor‐
mance influence for applications using this resource. The criti‐
cal percentage depends on the type of resource: e.g. the perfor‐
mance influence of a disk with a busy percentage of 80% might be
more noticeable for applications/users than a CPU with a busy per‐
centage of 90%.
Currently pcp-atop uses the following default values to calculate
a weighted percentage per resource:
Processor
A busy percentage of 90% or higher is considered 'critical'
(also in bar graph mode).
Disk
A busy percentage of 90% or higher is considered 'critical'.
Network
A busy percentage of 90% or higher for the load of an inter‐
face is considered 'critical'.
Memory
An occupation percentage of 90% is considered 'critical'.
Notice that this occupation percentage is the accumulated
memory consumption of the kernel (including slab) and all
processes. The memory for the page cache ('cache' and 'buff'
in the MEM-line) and the reclaimable part of the slab
('slrec') is not implied!
If the number of pages swapped out ('swout' in the PAG-line)
is larger than 10 per second, the memory resource is consid‐
ered 'critical'. A value of at least 1 per second is consid‐
ered 'almost critical'.
If the committed virtual memory exceeds the limit ('vmcom'
and 'vmlim' in the SWP-line), the SWP-line is colored due to
overcommitting the system.
Swap
An occupation percentage of 80% is considered 'critical' be‐
cause swap space might be completely exhausted in the near
future. It is not critical from a performance point-of-view.
These default values can be modified in the configuration file
(see separate pcp-atoprc(5) man page).
When a resource exceeds its critical occupation percentage, the
concerning values in the screen line are colored red by default.
When a resource exceeds (by default) 80% of its critical percent‐
age (so it is almost critical), the concerning values in the
screen line are colored cyan by default. This 'almost critical
percentage' (one value for all resources) can be modified in the
configuration file (see separate pcp-atoprc(5) man page).
The default colors red and cyan can be modified in the configura‐
tion file as well (see separate man-page of pcp-atoprc(5)).
With the key 'x' (or flag -x), the use of colors can be suppressed
in text mode. The use of colors is however mandatory in case of
bar graph mode.
Per-process and per-thread network activity can be measured by the
netatop BPF module that can be separately installed with
pmdabpf(1). or pmdabcc(1).
When pcp-atop gathers counters for a new interval, it verifies if
the eBPF module is currently active. If so, pcp-atop obtains the
relevant network counters from this module and shows the number of
sent and received packets per process/thread in the generic
screen. Besides, detailed counters can be requested by pressing
the 'n' key.
GPU statistics can be gathered by pmdanvidia(1) which is a sepa‐
rate data collection daemon process. It gathers cumulative uti‐
lization counters of every Nvidia GPU in the system, as well as
utilization counters of every process that uses a GPU. When pcp-
atop notices that the daemon is active, it reads these GPU uti‐
lization counters with every interval.
Find a description about the utilization counters in the section
OUTPUT DESCRIPTION.
When running pcp-atop interactively (no output redirection), keys
can be pressed to control the output. In general, lower case keys
can be used to show other information for the active processes
while certain upper case keys can be used to influence the sort
order of the active process/thread list. Some of these keys can
also be used to switch from bar graph mode to particular detailed
process information in text mode.
g Show generic output (default).
Per process the following fields are shown in case of a win‐
dow-width of 80 positions: process-id, CPU consumption during
the last interval in system and user mode, the virtual and
resident memory growth of the process.
The data transfer per process for read/write on disk can only
be shown when pcp-atop accesses metrics with root privileges.
When the optional pmdabpf(1) or pmdabcc(1) module netatop is
loaded, the data transfer for send/receive of network packets
is shown for each process.
The last columns contain the state, the occupation percentage
for the chosen resource (default: CPU) and the process name.
When more than 80 positions are available, other information
is added.
m Show memory related output.
Per process the following fields are shown in case of a win‐
dow width of 80 positions: process-id, minor and major memory
faults, size of virtual shared text, total virtual process
size, total resident process size, virtual and resident
growth during last interval, memory occupation percentage and
process name.
When more than 80 positions are available, other information
is added.
For memory consumption, always all processes are shown (also
the processes that were not active during the interval).
d Show disk-related output.
When pcp-atop runs with root privileges, the following fields
are shown: process-id, amount of data read from disk, amount
of data written to disk, amount of data that was written but
has been withdrawn again (WCANCL), disk occupation percentage
and process name.
n Show network related output.
Per process the following fields are shown in case of a win‐
dow width of 80 positions: process-id, thread-id, total band‐
width for received packets, total bandwidth for sent packets,
number of received TCP packets with the average size per
packet (in bytes), number of sent TCP packets with the aver‐
age size per packet (in bytes), number of received UDP pack‐
ets with the average size per packet (in bytes), number of
sent UDP packets with the average size per packet (in bytes),
the network occupation percentage and process name.
This information can only be shown when the optional
pmdabpf(1) or pmdabcc(1) module netatop is installed.
When more than 80 positions are available, other information
is added.
s Show scheduling characteristics.
Per process the following fields are shown in case of a win‐
dow width of 80 positions: process-id, number of threads in
state 'running' (R), number of threads in state 'interrupt‐
ible sleeping' (S), number of threads in state 'uninterrupt‐
ible sleeping' (D), number of threads in state 'idle' (I),
scheduling policy (normal timesharing, realtime round-robin,
realtime fifo), nice value, priority, realtime priority, cur‐
rent processor, status, exit code, state, the occupation per‐
centage for the chosen resource and the process name.
When more than 80 positions are available, other information
is added.
v Show various process characteristics.
Per process the following fields are shown in case of a win‐
dow width of 80 positions: process-id, user name and group,
start date and time, status (e.g. exit code if the process
has finished), state, the occupation percentage for the cho‐
sen resource and the process name.
When more than 80 positions are available, other information
is added.
c Show the command line of the process.
Per process the following fields are shown: process-id, the
occupation percentage for the chosen resource and the command
line including arguments.
X Show cgroup v2 information.
Per process the following fields are shown: process-id, the
command name, and the cgroup path name (horizontally scrol‐
lable).
e Show GPU utilization.
Per process at least the following fields are shown: process-
id, range of GPU numbers on which the process currently runs,
GPU busy percentage on all GPUs, memory busy percentage (i.e.
read and write accesses on memory) on all GPUs, memory occu‐
pation at the moment of the sample, average memory occupation
during the sample, and GPU percentage.
When the pmdanvidia daemon does not run with root privileges,
the GPU busy percentage and the memory busy percentage are
not available on process level. In that case, the GPU per‐
centage on process level reflects the GPU memory occupation
instead of the GPU busy percentage (which is preferred).
o Show the user-defined line of the process.
In the configuration file the keyword ownprocline can be
specified with the description of a user-defined output-line.
Refer to the man-page of pcp-atoprc(5) for a detailed de‐
scription.
y Show the individual threads within a process (toggle).
Single-threaded processes are still shown as one line.
For multi-threaded processes, one line represents the process
while additional lines show the activity per individual
thread (in a different color). Depending on the option 'a'
(all or active toggle), all threads are shown or only the
threads that were active during the last interval. Depending
on the option 'Y' (sort threads), the threads per process
will be sorted on the chosen sort criterion or not.
Whether this key is active or not can be seen in the header
line.
Y Sort the threads per process when combined with option 'y'
(toggle).
u Show the process activity accumulated per user.
Per user the following fields are shown: number of processes
active or terminated during last interval (or in total if
combined with command 'a'), accumulated CPU consumption dur‐
ing last interval in system and user mode, the current virtu‐
al and resident memory space consumed by active processes (or
all processes of the user if combined with command 'a').
When pcp-atop access metrics with root privileges, the accu‐
mulated read and write throughput on disk is shown. When the
optional pmdabpf(1) or pmdabcc(1) module 'netproc' has been
installed, the number of receive and send network calls are
shown.
The last columns contain the accumulated occupation percent‐
age for the chosen resource (default: CPU) and the user name.
p Show the process activity accumulated per program (i.e.
process name).
Per program the following fields are shown: number of
processes active or terminated during last interval (or in
total if combined with command 'a'), accumulated CPU consump‐
tion during last interval in system and user mode, the cur‐
rent virtual and resident memory space consumed by active
processes (or all processes of the user if combined with com‐
mand 'a').
When pcp-atop access metrics with root privileges, the accu‐
mulated read and write throughput on disk is shown. When the
pmdabcc(1) module 'netproc' has been installed, the number of
receive and send network calls are shown.
The last columns contain the accumulated occupation percent‐
age for the chosen resource (default: CPU) and the program
name.
j Show the process activity accumulated per container/pod.
Per container (e.g. Docker/Podman) or pod (e.g. Kubernetes)
the following fields are shown: number of processes active or
terminated during last interval (or in total if combined with
command 'a'), accumulated CPU consumption during last inter‐
val in system and user mode, the current virtual and resident
memory space consumed by active processes (or all processes
of the user if combined with command 'a').
When pcp-atop access metrics with root privileges, the accu‐
mulated read and write throughput on disk is shown. When the
pmdabpf(1) or pmdabcc(1) module 'netproc' has been installed,
the number of receive and send network calls are shown.
The last columns contain the accumulated occupation percent‐
age for the chosen resource (default: CPU) and the contain‐
er/pod name (CID/POD).
C Sort the current list in the order of CPU consumption (de‐
fault). The one-but-last column changes to 'CPU'.
E Sort the current list in the order of GPU utilization (pre‐
ferred, but only applicable when the pmdanvidia daemon runs
under root privileges) or the order of GPU memory occupa‐
tion). The one-but-last column changes to 'GPU'.
M Sort the current list in the order of resident memory con‐
sumption. The one-but-last column changes to 'MEM'. In case
of sorting on memory, the full process list will be shown
(not only the active processes).
D Sort the current list in the order of disk accesses issued.
The one-but-last column changes to 'DSK'.
N Sort the current list in the order of network bandwidth (re‐
ceived and transmitted). The one-but-last column changes to
'NET'.
A Sort the current list automatically in the order of the most
busy system resource during this interval. The one-but-last
column shows either 'ACPU', 'AMEM', 'ADSK' or 'ANET' (the
preceding 'A' indicates automatic sorting-order). The most
busy resource is determined by comparing the weighted busy-
percentages of the system resources, as described earlier in
the section COLORS.
This option remains valid until another sorting-order is ex‐
plicitly selected again.
A sorting order for disk is only possible when pcp-atop runs
with root privileges. A sorting-order for network is only
possible when the pmdabpf(1) or pmdabcc(1) module 'netproc'
has been installed.
Miscellaneous interactive commands:
? Request for help information (also the key 'h' can be
pressed).
V Request for version information (version number and date).
R Gather and calculate the proportional set size of processes
(toggle). Gathering of all values that are needed to calcu‐
late the PSIZE of a process is a very time-consuming task, so
this key should only be active when analyzing the resident
memory consumption of processes.
W Get the WCHAN per thread (toggle). Gathering of the WCHAN
string per thread is a relatively time-consuming task, so
this key should only be made active when analyzing the reason
for threads to be in sleep state.
x Suppress colors to highlight critical resources (toggle).
Whether this key is active or not can be seen in the header
line.
z The pause key can be used to freeze the current situation in
order to investigate the output on the screen. While pcp-
atop is paused, the keys described above can be pressed to
show other information about the current list of processes.
Whenever the pause key is pressed again, pcp-atop will con‐
tinue with the next sample.
The pause key can be used in text mode and bar graph mode.
i Modify the interval timer (default: 10 seconds). If an in‐
terval timer of 0 is entered, the interval timer is switched
off. In that case a new sample can only be triggered manual‐
ly by pressing the key 't'.
The interval can be modified in text mode and bar graph mode.
t Trigger a new sample manually. This key can be pressed if
the current sample should be finished before the timer has
exceeded, or if no timer is set at all (interval timer de‐
fined as 0). In the latter case pcp-atop can be used as a
stopwatch to measure the load being caused by a particular
application transaction, without knowing on beforehand how
many seconds this transaction will last.
This key can be used in text mode and bar graph mode.
When viewing the contents of an archive folio, this key can
be used to show the next sample from the folio.
T When viewing the contents of an archive folio, this key can
be used to show the previous sample from the folio.
This key can be used in text mode and bar graph mode.
b When viewing the contents of an archive folio, this key can
be used to move to a certain timestamp within the file (ei‐
ther forward or backward).
This key can be used in text mode and bar graph mode.
r Reset all counters to zero to see the system and process ac‐
tivity since boot again.
This key can be used in text mode and bar graph mode.
When viewing the contents of an archive, this key can be used
to rewind to the beginning of the file again.
U Specify a search string for specific user names as a regular
expression. From now on, only (active) processes will be
shown from a user which matches the regular expression. The
system statistics are still system wide. If the Enter-key is
pressed without specifying a name, (active) processes of all
users will be shown again.
Whether this key is active or not can be seen in the header
line.
I Specify a list with one or more PIDs to be selected. From
now on, only processes will be shown with a PID which matches
one of the given list. The system statistics are still sys‐
tem wide. If the Enter-key is pressed without specifying a
PID, all (active) processes will be shown again.
Whether this key is active or not can be seen in the header
line.
P Specify a search string for specific process names as a regu‐
lar expression. From now on, only processes will be shown
with a name which matches the regular expression. The system
statistics are still system wide. If the Enter-key is
pressed without specifying a name, all (active) processes
will be shown again.
Whether this key is active or not can be seen in the header
line.
/ Specify a specific command line search string as a regular
expression. From now on, only processes will be shown with a
command line which matches the regular expression. The sys‐
tem statistics are still system wide. If the Enter-key is
pressed without specifying a string, all (active) processes
will be shown again.
Whether this key is active or not can be seen in the header
line.
J Specify a container id (e.g. Docker or Podman) or pod name
(e.g. Kubernetes) of maximum 15 characters. In case the name
is longer, the last 15 characters are expected. From now on,
only processes will be shown that run in that specific con‐
tainer or pod. The system statistics are still system wide.
If the Enter-key is pressed without specifying a container id
or pod name, all (active) processes will be shown again.
Whether this key is active or not can be seen in the header
line.
Q Specify a comma-separated list of process state characters.
From now on, only processes will be shown that are in those
specific process states. Accepted states are: R (running), S
(sleeping), D (disk sleep), T (stopped), t (tracing stop), X
(dead), Z (zombie) and P (parked). The system statistics are
still system wide. If the Enter-key is pressed without spec‐
ifying a state, all (active) processes will be shown again.
Whether this key is active or not can be seen in the header
line.
S Specify search strings for specific logical volume names,
specific disk names and specific network interface names.
All search strings are interpreted as a regular expressions.
From now on, only those system resources are shown that match
the concerning regular expression. If the Enter-key is
pressed without specifying a search string, all (active) sys‐
tem resources of that type will be shown again.
Whether this key is active or not can be seen in the header
line.
a The 'all/active' key can be used to toggle between only show‐
ing/accumulating the processes that were active during the
last interval (default) or showing/accumulating all process‐
es.
Whether this key is active or not can be seen in the header
line.
G By default, pcp-atop shows/accumulates the processes that are
alive and the processes that are exited during the last in‐
terval. With this key (toggle), showing/accumulating the
processes that are exited can be suppressed.
Whether this key is active or not can be seen in the header
line.
f Show a fixed (maximum) number of header lines for system re‐
sources (toggle). By default only the lines are shown about
system resources (CPUs, paging, logical volumes, disks, net‐
work interfaces) that really have been active during the last
interval. With this key you can force pcp-atop to show lines
of inactive resources as well.
Whether this key is active or not can be seen in the header
line.
F Suppress sorting of system resources (toggle). By default
system resources (CPUs, logical volumes, disks, network in‐
terfaces) are sorted on utilization.
Whether this key is active or not can be seen in the header
line.
1 Show relevant counters as an average per second (in the for‐
mat '..../s') instead of as a total during the interval (tog‐
gle).
Whether this key is active or not can be seen in the header
line.
l Limit the number of system level lines for the counters per-
cpu, the active disks and the network interfaces. By default
lines are shown of all CPUs, disks and network interfaces
which have been active during the last interval. Limiting
these lines can be useful on systems with huge number CPUs,
disks or interfaces in order to be able to run pcp-atop on a
screen/window with e.g. only 24 lines.
For all mentioned resources the maximum number of lines can
be specified interactively. When using the flag -l the maxi‐
mum number of per-cpu lines is set to 0, the maximum number
of disk lines to 5 and the maximum number of interface lines
to 3. These values can be modified again in interactive
mode.
k Send a signal to an active process (a.k.a. kill a process).
q Quit the program.
This key can be used in text mode and bar graph mode.
PgDn Show the next page of the process/thread list.
With the arrow-down key the list can be scrolled downwards
with single lines.
^F Show the next page of the process/thread list (forward).
With the arrow-down key the list can be scrolled downwards
with single lines.
PgUp Show the previous page of the process/thread list.
With the arrow-up key the list can be scrolled upwards with
single lines.
^B Show the previous page of the process/thread list (backward).
With the arrow-up key the list can be scrolled upwards with
single lines.
^L Redraw the screen.
In order to store system and process level statistics for long-
term analysis (e.g. to check the system load and the active
processes running yesterday between 3:00 and 4:00 PM), pcp-atop
can store the system and process level statistics in the PCP
archive format, as an archive folio (see mkaf(1)).
All information about processes and threads is stored in the
archive.
The interval (default: 10 seconds) and number of samples (default:
infinite) can be passed as last arguments. Instead of the number
of samples, the flag -S can be used to indicate that pcp-atop
should finish anyhow before midnight.
A PCP archive can be read and visualized again with the -r option.
The argument is a comma-separated list of names, each of which may
be the base name of an archive or the name of a directory contain‐
ing one or more archives. If no argument is specified, the file
$PCP_LOG_DIR/pmlogger/HOST/YYYYMMDD is opened for input (where
YYYYMMDD are digits representing the current date, and HOST is the
hostname of the machine being logged). If a filename is specified
in the format YYYYMMDD (representing any valid date), the file
$PCP_LOG_DIR/pmlogger/HOST/YYYYMMDD is opened. If a filename with
the symbolic name y is specified, yesterday's daily logfile is
opened (this can be repeated so 'yyyy' indicates the logfile of
four days ago).
The samples from the file can be viewed interactively by using the
key 't' to show the next sample, the key 'T' to show the previous
sample, the key 'b' to branch to a particular time or the key 'r'
to rewind to the beginning of the file. These keys can be used in
text mode as well as in bar graph mode.
When output is redirected to a file or pipe, pcp-atop prints all
samples in plain ASCII. The default line length is 80 characters
in that case. With the flag -L followed by an alternate line
length, more (or less) columns will be shown.
With the flag -b (begin time) and/or -e (end time) followed by a
time argument of the form [YYYYMMDD]hhmm[ss], a certain time peri‐
od within the archive can be selected.
The first sample shows the system level activity since boot (the
elapsed time in the header shows the time since boot).
In text mode, pcp-atop first shows the lines related to system
level activity for every sample. If a particular system resource
has not been used during the interval, the entire line related to
this resource is suppressed. So the number of system level lines
may vary for each sample.
After that a list is shown of processes which have been active
during the last interval. This list is by default sorted on CPU
consumption, but this order can be changed by the keys which are
previously described.
If values have to be shown by pcp-atop which do not fit in the
column width, another format is used. If e.g. a CPU consumption of
233216 milliseconds should be shown in a column width of 4 posi‐
tions, it is shown as '233s' (in seconds). For large memory fig‐
ures, another unit is chosen if the value does not fit (Mb instead
of Kb, Gb instead of Mb, Tb instead of Gb, etcetera). For other
values, a kind of exponent notation is used (value 123456789 shown
in a column of 5 positions gives 123e6).
The system level information in text mode consists of the follow‐
ing output lines:
PRC Process and thread level totals.
This line contains the total CPU time consumed in system mode
('sys') and in user mode ('user'), the total number of
processes present at this moment ('#proc'), the total number
of threads present at this moment in state 'running'
('#trun'), 'sleeping interruptible' ('#tslpi'), 'sleeping un‐
interruptible' ('#tslpu') and 'idle' ('#tidle'), the number
of zombie processes ('#zombie'), the number of clone system
calls ('clones'), and the number of processes that ended dur‐
ing the interval ('#exit') when process accounting is used.
Instead of '#exit' the last column may indicate that process
accounting could not be activated ('no procacct').
If the screen width does not allow all of these counters, on‐
ly a relevant subset is shown.
CPU CPU utilization.
At least one line is shown for the total occupation of all
CPUs together.
In case of a multi-processor system, an additional line is
shown for every individual processor (with 'cpu' in lower
case), sorted on activity. Inactive CPUs will not be shown
by default. The lines showing the per-cpu occupation contain
the CPU number in the field combined with the wait percent‐
age.
Every line contains the percentage of CPU time spent in ker‐
nel mode by all active processes ('sys'), the percentage of
cpu time consumed in user mode ('user') for all active
processes (including processes running with a nice value
larger than zero), the percentage of CPU time spent for in‐
terrupt handling ('irq') including softirq, the percentage of
unused CPU time while no processes were waiting for disk I/O
('idle'), and the percentage of unused CPU time while at
least one process was waiting for disk I/O ('wait').
In case of per-cpu occupation, the CPU number and the wait
percentage ('w') for that CPU. The number of lines showing
the per-cpu occupation can be limited.
For virtual machines, the steal-percentage ('steal') shows
the percentage of CPU time stolen by other virtual machines
running on the same hardware.
For physical machines hosting one or more virtual machines,
the guest-percentage ('guest') shows the percentage of CPU
time used by the virtual machines. Notice that this percent‐
age overlaps the user-percentage!
When PMC performance monitoring counters are supported by the
CPU and the kernel (and pmdaperfevent(1) runs with root priv‐
ileges), the number of instructions per CPU cycle ('ipc') is
shown. The first sample always shows the value 'initial',
because the counters are just activated at the moment that
pcp-atop is started.
When the CPU busy percentage is high and the IPC is less than
1.0, it is likely that the CPU is frequently waiting for mem‐
ory access during instruction execution (larger CPU caches or
faster memory might be helpful to improve performance). When
the CPU busy percentage is high and the IPC is greater than
1.0, it is likely that the CPU is instruction-bound
(more/faster cores might be helpful to improve performance).
Furthermore, per CPU the effective number of cycles ('cycl')
is shown. This value can reach the current CPU frequency if
such CPU is 100% busy. When an idle CPU is halted, the num‐
ber of effective cycles can be (considerably) lower than the
current frequency.
Notice that the average instructions per cycle and number of
cycles is shown in the CPU line for all CPUs.
See also:
http://www.brendangregg.com/blog/2017-05-09/cpu-utilization-is-wrong.html
In case of frequency scaling, all previously mentioned CPU
percentages are relative to the used scaling of the CPU dur‐
ing the interval. If a CPU has been active for e.g. 50% in
user mode during the interval while the frequency scaling of
that CPU was 40%, only 20% of the full capacity of the CPU
has been used in user mode.
In case that the kernel module 'cpufreq_stats' is active (af‐
ter issuing 'modprobe cpufreq_stats'), the average frequency
('avgf') and the average scaling percentage ('avgscal') is
shown. Otherwise the current frequency ('curf') and the cur‐
rent scaling percentage ('curscal') is shown at the moment
that the sample is taken. Notice that average values for
frequency and scaling are shown in the CPU line for every
CPU.
Frequency scaling statistics are only gathered for systems
with maximum 8 CPUs, since gathering of these values per CPU
is very time consuming.
If the screen-width does not allow all of these counters, on‐
ly a relevant subset is shown.
CPL CPU load information.
This line contains the load average figures reflecting the
number of threads that are available to run on a CPU (i.e.
part of the runqueue) or that are waiting for disk I/O. These
figures are averaged over 1 ('avg1'), 5 ('avg5') and 15
('avg15') minutes.
Furthermore the number of context switches ('csw'), the num‐
ber of serviced interrupts ('intr') and the number of avail‐
able CPUs are shown.
If the screen-width does not allow all of these counters, on‐
ly a relevant subset is shown.
GPU GPU utilization (Nvidia).
Read the section GPU STATISTICS GATHERING in this document to
find the details about the activation of the pmdanvidia dae‐
mon.
In the first column of every line, the bus-id (last nine
characters) and the GPU number are shown. The subsequent
columns show the percentage of time that one or more kernels
were executing on the GPU ('gpubusy'), the percentage of time
that global (device) memory was being read or written ('mem‐
busy'), the occupation percentage of memory ('memocc'), the
total memory ('total'), the memory being in use at the moment
of the sample ('used'), the average memory being in use dur‐
ing the sample time ('usavg'), the number of processes being
active on the GPU at the moment of the sample ('#proc'), and
the type of GPU.
If the screen-width does not allow all of these counters, on‐
ly a relevant subset is shown.
The number of lines showing the GPUs can be limited.
MEM Memory occupation (two lines).
These lines contain the total amount of physical memory
('tot'), the amount of memory which is currently free
('free'), the amount of memory that is available for new
workloads without pushing the system into swap ('avail'), the
amount of memory in use as page cache including the total
resident shared memory ('cache'), the amount of memory within
the page cache that has to be flushed to disk ('dirty'), the
amount of memory used for filesystem meta data ('buff'), the
amount of memory being used for kernel mallocs ('slab'), the
amount of slab memory that is reclaimable ('slrec'), the res‐
ident size of SYSV shared memory including tmpfs but exclud‐
ing static huge pages ('shmem'), the resident size of SYSV
shared memory including static huge pages ('shrss'), the
amount of SYSV shared memory that is currently swapped
('shswp'), the amount of memory that is currently used for
page tables ('pgtab'), the number of NUMA nodes in this sys‐
tem ('numnode'), the amount of memory that is currently
claimed by vmware's balloon driver ('vmbal'), the amount of
memory that is currently claimed by the ARC (cache) of ZFSon‐
linux ('zfarc'), the amount of memory for anonymous transpar‐
ent huge pages ('anthp'), the amount of memory that is
claimed for huge pages ('hptot'), the amount of huge page
memory that is really in use ('hpuse'), the amount of memory
that is used for TCP sockets ('tcps'), and the amount of mem‐
ory that is used for UDP sockets ('udps').
If the screen-width does not allow all of these counters, on‐
ly a relevant subset is shown.
SWP Swap occupation and overcommit info.
This line contains the total amount of swap space on disk
('tot') and the amount of free swap space ('free'), the size
of the swap cache ('swcac'), the size of compressed storage
used for zswap ('zswap'), the real (decompressed) size of the
pages stored in zswap ('zstor'), the total size of the memory
used for KSM ('ksuse', i.e. shared), and the total size of
the memory saved (deduped) by KSM ('kssav', i.e. sharing).
Furthermore the committed virtual memory space ('vmcom') and
the maximum limit of the committed space ('vmlim', which is
by default swap size plus 50% of memory size) is shown. The
committed space is the reserved virtual space for all alloca‐
tions of private memory space for processes. The kernel only
verifies whether the committed space exceeds the limit if
strict overcommit handling is configured (vm.overcommit_memo‐
ry is 2).
LLC Last-Level Cache of CPU info.
This line contains the total memory bandwidth of LLC ('tot'),
the bandwidth of the local NUMA node ('loc'), and the per‐
centage of LLC in use ('LLCXX YY%').
Note that this feature depends on the 'resctrl' pseudo
filesystem. Be sure that the kernel is built with the rele‐
vant config and take care that the pseudo-filesystem is
mounted:
mount -t resctrl resctrl -o mba_MBps /sys/fs/resctrl (on
Intel)
mount -t resctrl resctrl -o cdp /sys/fs/resctrl (on
AMD)
NUM Memory utilization per NUMA node (not shown for single NUMA
node).
This line shows the total amount of physical memory of this
node ('tot'), the amount of free memory ('free'), the amount
of memory for cached file data ('file'), modified cached file
data ('dirty'), recently used memory ('activ'), less recently
used memory ('inact'), memory being used for kernel mallocs
('slab'), the amount of slab memory that is reclaimable
('slrec'), shared memory including tmpfs ('shmem'), total
huge pages ('hptot'), used huge pages('hpuse'), and the frag‐
mentation percentage ('frag').
NUC CPU utilization per NUMA node (not shown for single NUMA
node).
This line shows the utilization percentages of all CPUs re‐
lated to this NUMA node, categorized for system mode
('sys'), user mode ('user'), user mode for niced processes
('niced'), idle mode ('idle'), wait mode ('w' preceded by the
node number), irq mode ('irq'), softirq mode ('sirq'), steal
mode ('steal'), and guest mode ('guest') overlapping user
mode.
PAG Paging frequency.
This line contains the number of scanned pages ('scan') due
to the fact that free memory drops below a particular thresh‐
old, the number of times that the kernel tries to reclaim
pages due to an urgent need ('stall'), the number of process
stalls to run memory compaction to allocate huge pages ('com‐
pact'), the number of NUMA pages migrated ('numamig'), and
the total number of memory pages migrated successfully e.g.
between NUMA nodes or for compaction ('migrate') are shown.
Also the number of memory pages the system read from block
devices ('pgin'), the number of memory pages the system wrote
to block devices ('pgout'), the number of memory pages
swapped in from zswap ('zswin'), the number of memory pages
swapped out to zswap ('zswout'), the number of memory pages
the system read from swap space ('swin'), the number of memo‐
ry pages the system wrote to swap space ('swout'), and the
number of out-of-memory kills ('oomkill').
PSI Pressure Stall Information.
This line contains percentages about resource pressure relat‐
ed to CPU, memory and I/O. Certain percentages refer to
'some' meaning that some processes/threads were delayed due
to resource overload. Other percentages refer to 'full' mean‐
ing a loss of overall throughput due to resource overload.
The values 'cpusome', 'memsome', 'memfull', 'iosome' and 'io‐
full' show the pressure percentage during the entire inter‐
val.
The values 'cs' (cpu some), 'ms' (memory some), 'mf' (memory
full), ´is' (I/O some) and 'if' (I/O full) each show three
percentages separated by slashes: pressure percentage over
the last 10, 60 and 300 seconds.
LVM/MDD/DSK
Logical volume/multiple device/disk utilization.
Per active unit one line is produced, sorted on unit activi‐
ty. Such line shows the name (e.g. VolGroup00-lvtmp for a
logical volume or sda for a hard disk), the percentage of
elapsed time during which I/O requests were issued to the de‐
vice ('busy') (note that for devices serving requests in par‐
allel, such as RAID arrays, SSD and NVMe, this number does
not reflect their performance limits), the number of read re‐
quests issued ('read'), the number of write requests issued
('write'), the number of discard requests issued ('discrd')
if supported by kernel version, the number of KiBytes per
read ('KiB/r'), the number of KiBytes per write ('KiB/w'),
the number of KiBytes per discard ('KiB/d') if supported by
kernel version, the number of MiBytes per second throughput
for reads ('MBr/s'), the number of MiBytes per second
throughput for writes ('MBw/s'), requests issued to the de‐
vice driver but not completed ('inflt'), the average queue
depth ('avq') and the average number of milliseconds needed
by a request ('avio') for seek, latency and data transfer.
If the screen-width does not allow all of these counters, on‐
ly a relevant subset is shown.
The number of lines showing the units can be limited per
class (LVM, MDD or DSK) with the 'l' key or statically (see
separate man-page of pcp-atoprc(5)). By specifying the value
0 for a particular class, no lines will be shown any more for
that class.
NFM Network Filesystem (NFS) mount at the client side.
For each NFS-mounted filesystem, a line is shown that con‐
tains the mounted server directory, the name of the server
('srv'), the total number of bytes physically read from the
server ('read') and the total number of bytes physically
written to the server ('write'). Data transfer is subdivided
in the number of bytes read via normal read() system calls
('nread'), the number of bytes written via normal read() sys‐
tem calls ('nwrit'), the number of bytes read via direct I/O
('dread'), the number of bytes written via direct I/O
('dwrit'), the number of bytes read via memory mapped I/O
pages ('mread'), and the number of bytes written via memory
mapped I/O pages ('mwrit').
NFC Network Filesystem (NFS) client side counters.
This line contains the number of RPC calls issues by local
processes ('rpc'), the number of read RPC calls ('read') and
write RPC calls ('rpwrite') issued to the NFS server, the
number of RPC calls being retransmitted ('retxmit') and the
number of authorization refreshes ('autref').
NFS Network Filesystem (NFS) server side counters.
This line contains the number of RPC calls received from NFS
clients ('rpc'), the number of read RPC calls received
('cread'), the number of write RPC calls received ('cwrit'),
the number of Megabytes/second returned to read requests by
clients ('MBcr/s'), the number of Megabytes/second passed in
write requests by clients ('MBcw/s'), the number of network
requests handled via TCP ('nettcp'), the number of network
requests handled via UDP ('netudp'), the number of reply
cache hits ('rchits'), the number of reply cache misses
('rcmiss') and the number of uncached requests ('rcnoca').
Furthermore some error counters indicating the number of re‐
quests with a bad format ('badfmt') or a bad authorization
('badaut'), and a counter indicating the number of bad
clients ('badcln').
NET Network utilization (TCP/IP).
One line is shown for activity of the transport layer (TCP
and UDP), one line for the IP layer and one line per active
interface.
For the transport layer, counters are shown concerning the
number of received TCP segments including those received in
error ('tcpi'), the number of transmitted TCP segments ex‐
cluding those containing only retransmitted octets ('tcpo'),
the number of UDP datagrams received ('udpi'), the number of
UDP datagrams transmitted ('udpo'), the number of active TCP
opens ('tcpao'), the number of passive TCP opens ('tcppo'),
the number of TCP output retransmissions ('tcprs'), the num‐
ber of TCP input errors ('tcpie'), the number of TCP output
resets ('tcpor'), the number of UDP no ports ('udpnp'), the
number of UDP input errors ('udpie'), and the number of TCP
incorrect checksums ('csumie').
If the screen-width does not allow all of these counters, on‐
ly a relevant subset is shown.
These counters are related to IPv4 and IPv6 combined.
For the IP layer, counters are shown concerning the number of
IP datagrams received from interfaces, including those re‐
ceived in error ('ipi'), the number of IP datagrams that lo‐
cal higher-layer protocols offered for transmission ('ipo'),
the number of received IP datagrams which were forwarded to
other interfaces ('ipfrw'), the number of IP datagrams which
were delivered to local higher-layer protocols ('deliv'), the
number of received ICMP datagrams ('icmpi'), and the number
of transmitted ICMP datagrams ('icmpo').
If the screen-width does not allow all of these counters, on‐
ly a relevant subset is shown.
These counters are related to IPv4 and IPv6 combined.
For every active network interface one line is shown, sorted
on the interface activity. Such line shows the name of the
interface and its busy percentage in the first column. The
busy percentage for half duplex is determined by comparing
the interface speed with the number of bits transmitted and
received per second; for full duplex the interface speed is
compared with the highest of either the transmitted or the
received bits. When the interface speed can not be deter‐
mined (e.g. for the loopback interface), '---' is shown in‐
stead of the percentage.
Furthermore the number of received packets ('pcki'), the num‐
ber of transmitted packets ('pcko'), the line speed of the
interface ('sp'), the effective amount of bits received per
second ('si'), the effective amount of bits transmitted per
second ('so'), the number of collisions ('coll'), the number
of received multicast packets ('mlti'), the number of errors
while receiving a packet ('erri'), the number of errors while
transmitting a packet ('erro'), the number of received pack‐
ets dropped ('drpi'), and the number of transmitted packets
dropped ('drpo').
If the screen-width does not allow all of these counters, on‐
ly a relevant subset is shown.
The number of lines showing the network interfaces can be
limited.
IFB Infiniband utilization.
For every active Infiniband port one line is shown, sorted on
activity. Such line shows the name of the port and its busy
percentage in the first column. The busy percentage is de‐
termined by taking the highest of either the transmitted or
the received bits during the interval, multiplying that value
by the number of lanes and comparing it against the maximum
port speed.
Furthermore the number of received packets divided by the
number of lanes ('pcki'), the number of transmitted packets
divided by the number of lanes ('pcko'), the maximum line
speed ('sp'), the effective amount of bits received per sec‐
ond ('si'), the effective amount of bits transmitted per sec‐
ond ('so'), and the number of lanes ('lanes').
If the screen-width does not allow all of these counters, on‐
ly a relevant subset is shown.
The number of lines showing the Infiniband ports can be lim‐
ited.
Following the system level information, a list of processes is
shown in text mode from which the resource utilization has changed
during the last interval. These processes might have used CPU
time or issued disk or network requests. However a process is al‐
so shown if part of it has been paged out due to lack of memory
(while the process itself was in sleep state).
Per process the following fields may be shown (in alphabetical or‐
der), depending on the current output mode as described in the
section INTERACTIVE COMMANDS and depending on the current width of
your window:
AVGRSZ The average size of one read-action on disk.
AVGWSZ The average size of one write-action on disk.
BANDWI Total bandwidth for received TCP and UDP packets consumed
by this process (bits-per-second). This value can be
compared with the value 'si' on interface level (used
bandwidth per interface).
This information will only be shown when the optional
pmdabpf(1) or pmdabcc(1) module 'netproc' has been in‐
stalled.
BANDWO Total bandwidth for sent TCP and UDP packets consumed by
this process (bits-per-second). This value can be com‐
pared with the value 'so' on interface level (used band‐
width per interface).
This information will only be shown when the optional
pmdabpf(1) or pmdabcc(1) module 'netproc' has been in‐
stalled.
BDELAY Aggregated block I/O delay, i.e. time waiting for disk
I/O.
CGROUP Path name of the cgroup (version 2) to which this process
belongs. This path name is relative to the cgroup root
directory, which is usually '/sys/fs/cgroup'.
CID/POD Container id (e.g. Docker or Podman) or pod name (e.g.
Kubernetes) referring to the container/pod in which the
process/thread is running. When a pod name is longer
than 15 characters, only the last 15 characters are
shown.
If a process has been started and finished during the
last interval, a '?' is shown because the container id or
pod name is not part of the standard process accounting
record.
This column will only be shown when atop runs with supe‐
ruser privileges and when at least one containerized
process is detected.
CMD The name of the process. This name can be surrounded by
"less/greater than" signs ('<name>') which means that the
process has finished during the last interval. A single
accounting record is written for the entire process on
termination of the last thread in the process. When the
main thread exits, the process name is changed to the
thread name.
Behind the abbreviation 'CMD' in the header line, the
current page number and the total number of pages of the
process/thread list are shown.
COMMAND-LINE
The full command line of the process (including argu‐
ments). If the length of the command line exceeds the
length of the screen line, the arrow keys -> and <- can
be used for horizontal scroll.
The '-z <regex>' command line option can be used to
prepend matching environment variables to the displayed
command line. POSIX Extended Regular Expression syntax
are used (see regex(3)). When a matching environment
variable is too long (exceeding the buffer that should
contain the command line), it will be truncated.
Behind the verb 'COMMAND-LINE' in the header line, the
current page number and the total number of pages of the
process/thread list are shown.
CPU The occupation percentage of this process related to the
available capacity for this resource on system level.
CPUNR The identification of the CPU the (main) thread is run‐
ning on or has recently been running on.
CTID Container ID (OpenVZ). If a process has been started and
finished during the last interval, a '?' is shown because
the container ID is not part of the standard process ac‐
counting record.
DSK The occupation percentage of this process related to the
total load that is produced by all processes (i.e. total
disk accesses by all processes during the last interval).
This information is shown when per process "storage ac‐
counting" is active in the kernel.
EGID Effective group-id under which this process executes.
ENDATE Date that the process has been finished. If the process
is still running, this field shows 'active'.
ENTIME Time that the process has been finished. If the process
is still running, this field shows 'active'.
ENVID Virtual environment identified (OpenVZ only).
EUID Effective user-id under which this process executes.
EXC The exit code of a terminated process (second position of
column 'ST' is E) or the fatal signal number (second po‐
sition of column 'ST' is S or C).
FSGID Filesystem group-id under which this process executes.
FSUID Filesystem user-id under which this process executes.
GPU When the pmdanvidia daemon does not run with root privi‐
leges, the GPU percentage reflects the GPU memory occupa‐
tion percentage (memory of all GPUs is 100%).
When the pmdanvidia daemon runs with root privileges, the
GPU percentage reflects the GPU busy percentage.
GPUBUSY Busy percentage on all GPUs (one GPU is 100%).
When the pmdanvidia daemon does not run with root privi‐
leges, this value is not available.
GPUNUMS Comma-separated list of GPUs used by the process during
the interval. When the comma-separated list exceeds the
width of the column, a hexadecimal value is shown.
LOCKSZ The virtual amount of memory being locked (i.e. non-swap‐
pable) by this process (or user).
MAJFLT The number of page faults issued by this process that
have been solved by creating/loading the requested memory
page.
MEM The occupation percentage of this process related to the
available capacity for this resource on system level.
MEMAVG Average memory occupation during the interval on all used
GPUs.
MEMBUSY Busy percentage of memory on all GPUs (one GPU is 100%),
i.e. the time needed for read and write accesses on mem‐
ory.
When the pmdanvidia daemon does not run with root privi‐
leges, this value is not available.
MEMNOW Memory occupation at the moment of the sample on all used
GPUs.
MINFLT The number of page faults issued by this process that
have been solved by reclaiming the requested memory page
from the free list of pages.
NET The occupation percentage of this process related to the
total load that is produced by all processes (i.e. con‐
sumed network bandwidth of all processes during the last
interval).
This information will only be shown when the optional
pmdabpf(1) or pmdabcc(1) module 'netproc' has been in‐
stalled.
NICE The more or less static priority that can be given to a
process on a scale from -20 (high priority) to +19 (low
priority).
NIVCSW Number of times the process/thread was context-switched
involuntarily, in case that the time slice expired.
NPROCS The number of active and terminated processes accumulated
for this user or program.
NVCSW Number of times that the process/thread was context-
switched voluntarily in case of a blocking system call,
e.g. to wait for an I/O operation to complete.
PID Process-id.
POLI The policies 'norm' (normal, which is SCHED_OTHER),
'btch' (batch) and 'idle' refer to timesharing processes.
The policies 'fifo' (SCHED_FIFO) and 'rr' (round robin,
which is SCHED_RR) refer to realtime processes.
PPID Parent process-id.
PRI The process' priority ranges from 0 (highest priority) to
139 (lowest priority). Priority 0 to 99 are used for re‐
altime processes (fixed priority independent of their be‐
havior) and priority 100 to 139 for timesharing processes
(variable priority depending on their recent CPU consump‐
tion and the nice value).
PSIZE The proportional memory size of this process (or user).
Every process shares resident memory with other process‐
es. E.g. when a particular program is started several
times, the code pages (text) are only loaded once in mem‐
ory and shared by all incarnations. Also the code of
shared libraries is shared by all processes using that
shared library, as well as shared memory and memory-
mapped files. For the PSIZE calculation of a process,
the resident memory of a process that is shared with oth‐
er processes is divided by the number of sharers. This
means, that every process is accounted for a proportional
part of that memory. Accumulating the PSIZE values of
all processes in the system gives a reliable impression
of the total resident memory consumed by all processes.
Since gathering of all values that are needed to calcu‐
late the PSIZE is a very time-consuming task, the 'R' key
(or '-R' flag) should be active. Gathering these values
also requires superuser privileges (otherwise '?K' is
shown in the output).
RDDSK The read data transfer issued physically on disk (so
reading from the disk cache is not accounted for).
Unfortunately, the kernel aggregates the data transfer of
a process to the data transfer of its parent process when
terminating, so you might see transfers for (parent)
processes like cron, bash or init, that are not really
issued by them.
RDELAY Runqueue delay, i.e. time spent waiting on a runqueue.
RGID The real group-id under which the process executes.
RGROW The amount of resident memory that the process has grown
during the last interval. A resident growth can be
caused by touching memory pages which were not physically
created/loaded before (load-on-demand). Note that a res‐
ident growth can also be negative e.g. when part of the
process is paged out due to lack of memory or when the
process frees dynamically allocated memory. For a
process which started during the last interval, the resi‐
dent growth reflects the total resident size of the
process at that moment.
RNET The number of TCP- and UDP packets received by this
process. This information will only be shown when the
optional pmdabpf(1) or pmdabcc(1) netatop module is in‐
stalled.
If a process has finished during the last interval, no
value is shown since network counters are not part of the
standard process accounting record.
RSIZE The total resident memory usage consumed by this process
(or user). Notice that the RSIZE of a process includes
all resident memory used by that process, even if certain
memory parts are shared with other processes (see also
the explanation of PSIZE).
RTPR Realtime priority according the POSIX standard. Value
can be 0 for a timesharing process (policy 'norm', 'btch'
or 'idle') or ranges from 1 (lowest) till 99 (highest)
for a realtime process (policy 'rr' or 'fifo').
RUID The real user-id under which the process executes.
S The current state of the (main) thread: 'R' for running
(currently processing or in the runqueue), 'S' for sleep‐
ing interruptible (wait for an event to occur), 'D' for
sleeping non-interruptible, 'Z' for zombie (waiting to be
synchronized with its parent process), 'T' for stopped
(suspended or traced), 'W' for swapping, and 'E' (exit)
for processes which have finished during the last inter‐
val.
SGID The saved group-id of the process.
SNET The number of TCP and UDP packets transmitted by this
process. This information will only be shown when the
optional pmdabpf(1) or pmdabcc(1) netatop module is in‐
stalled.
ST The status of a process.
The first position indicates if the process has been
started during the last interval (the value N means 'new
process').
The second position indicates if the process has been
finished during the last interval.
The value E means 'exit' on the process' own initiative;
the exit code is displayed in the column 'EXC'.
The value S means that the process has been terminated
involuntarily by a signal; the signal number is displayed
in the in the column 'EXC'.
The value C means that the process has been terminated
involuntarily by a signal, producing a core dump in its
current directory; the signal number is displayed in the
column 'EXC'.
STDATE The start date of the process.
STTIME The start time of the process.
SUID The saved user-id of the process.
SWAPSZ The swap space consumed by this process (or user).
SYSCPU CPU time consumption of this process in system mode (ker‐
nel mode), usually due to system call handling.
TCPRASZ The average size of a received TCP buffer in bytes. This
information will only be shown when the optional
pmdabpf(1) or pmdabcc(1) netproc module is enabled.
TCPRCV The number of tcp_recvmsg()/tcp_cleanup_rbuf() calls from
this process. This information will only be shown when
the optional pmdabpf(1) or pmdabcc(1) netproc module is
enabled.
TCPSASZ The average size of a TCP buffer requested to be trans‐
mitted in bytes. This information will only be shown
when the optional pmdabpf(1) or pmdabcc(1) netproc module
is enabled.
TCPSND The number of tcp_sendmsg() calls from this process.
This information will only be shown when the optional
pmdabpf(1) or pmdabcc(1) netproc module is enabled.
THR Total number of threads within this process. All related
threads are contained in a thread group, represented by
pcp-atop as one line or as a separate line when the 'y'
key (or -y flag) is active.
TID Thread-id. All threads within a process run with the
same PID but with a different TID. This value is shown
for individual threads in multi-threaded processes (when
using the key 'y').
TIDLE Number of threads within this process that are in the
state 'idle' (I), i.e. uninterruptible sleeping threads
that do not count for the load average.
TRUN Number of threads within this process that are in the
state 'running' (R).
TSLPI Number of threads within this process that are in the
state 'interruptible sleeping' (S).
TSLPU Number of threads within this process that are in the
state 'uninterruptible sleeping' (D).
UDPRASZ The average size of a received UDP buffer in bytes. This
information will only be shown when the optional
pmdabpf(1) or pmdabcc(1) netproc module is enabled.
UDPRCV The number of udp_recvmsg()/skb_consume_udp() calls from
this process. This information will only be shown when
the optional pmdabpf(1) or pmdabcc(1) netproc module is
enabled.
UDPSASZ The average size of a UDP buffer requested to be trans‐
mitted in bytes. This information will only be shown
when the optional pmdabpf(1) or pmdabcc(1) netproc module
is enabled.
UDPSND The number of udp_sendmsg() calls from this process.
This information will only be shown when the optional
pmdabpf(1) or pmdabcc(1) netproc module is enabled.
USRCPU CPU time consumption of this process in user mode, due to
processing the own program text.
VDATA The virtual memory size of the private data used by this
process (including heap and shared library data).
VGROW The amount of virtual memory that the process has grown
during the last interval. A virtual growth can be caused
by e.g. issuing a malloc() or attaching a shared memory
segment. Note that a virtual growth can also be negative
by e.g. issuing a free() or detaching a shared memory
segment. For a process which started during the last in‐
terval, the virtual growth reflects the total virtual
size of the process at that moment.
VPID Virtual process-id (within an OpenVZ container). If a
process has been started and finished during the last in‐
terval, a '?' is shown because the virtual process-id is
not part of the standard process accounting record.
VSIZE The total virtual memory usage consumed by this process
(or user).
VSLIBS The virtual memory size of the (shared) text of all
shared libraries used by this process.
VSTACK The virtual memory size of the (private) stack used by
this process
VSTEXT The virtual memory size of the (shared) text of the exe‐
cutable program.
WCHAN Wait channel of thread in sleep state, i.e. the name of
the kernel function in which the thread has been put
asleep.
Since determining the name string of the kernel function
is a relatively time-consuming task, the 'W' key (or '-W'
flag) should be active.
WRDSK The write data transfer issued physically on disk (so
writing to the disk cache is not accounted for). This
counter is maintained for the application process that
writes its data to the cache (assuming that this data is
physically transferred to disk later on). Notice that
disk I/O needed for swapping is not taken into account.
Unfortunately, the kernel aggregates the data transfer of
a process to the data transfer of its parent process when
terminating, so you might see transfers for (parent)
processes like cron, bash or init, that are not really
issued by them.
WCANCL The write data transfer previously accounted for this
process or another process that has been cancelled. Sup‐
pose that a process writes new data to a file and that
data is removed again before the cache buffers have been
flushed to disk. Then the original process shows the
written data as WRDSK, while the process that re‐
moves/truncates the file shows the unflushed removed data
as WCANCL.
With the flag -P followed by a list of one or more labels (comma-
separated), parsable output is produced for each sample. The la‐
bels that can be specified for system-level statistics correspond
to the labels (first verb of each line) that can be found in the
interactive output: "CPU", "cpu", "CPL", "GPU", "MEM", "SWP",
"PAG", "PSI", "LVM", "MDD", "DSK", "NFM", "NFC", "NFS", "NET",
"IFB", "LLC", "NUM" and "NUC".
For process-level statistics special labels are introduced: "PRG"
(general), "PRC" (CPU), "PRE" (GPU), "PRM" (memory), "PRD" (disk,
only if "storage accounting" is active) and "PRN" (only if the op‐
tional pmdabpf(1) or pmdabcc(1) netproc module is installed).
With the label "ALL", all system and process level statistics are
shown.
The command and command line in the parsable output might contain
spaces and are therefore by default surrounded by parenthesis.
However, since a space is often used as separator between the
fields by parsing tools, with the additional flag -Z it is possi‐
ble to exchange the spaces in the command (line) by underscores
and omit the parenthesis.
For every interval all requested lines are shown whereafter pcp-
atop shows a line just containing the label "SEP" as a separator
before the lines for the next sample are generated.
When a sample contains the values since boot, pcp-atop shows a
line just containing the label "RESET" before the lines for this
sample are generated.
The first part of each output-line consists of the following six
fields: label (the name of the label), host (the name of this ma‐
chine), epoch (the time of this interval as number of seconds
since 1-1-1970), date (date of this interval in format
YYYY/MM/DD), time (time of this interval in format HH:MM:SS), and
interval (number of seconds elapsed for this interval).
The subsequent fields of each output-line depend on the label:
CPU Subsequent fields: total number of clock-ticks per second
for this machine, number of processors, consumption for
all CPUs in system mode (clock-ticks), consumption for
all CPUs in user mode (clock-ticks), consumption for all
CPUs in user mode for niced processes (clock-ticks), con‐
sumption for all CPUs in idle mode (clock-ticks), con‐
sumption for all CPUs in wait mode (clock-ticks), con‐
sumption for all CPUs in irq mode (clock-ticks), consump‐
tion for all CPUs in softirq mode (clock-ticks), consump‐
tion for all CPUs in steal mode (clock-ticks), consump‐
tion for all CPUs in guest mode (clock-ticks) overlapping
user mode, frequency of all CPUs and frequency percentage
of all CPUs.
cpu Subsequent fields: total number of clock-ticks per second
for this machine, processor-number, consumption for this
CPU in system mode (clock-ticks), consumption for this
CPU in user mode (clock-ticks), consumption for this CPU
in user mode for niced processes (clock-ticks), consump‐
tion for this CPU in idle mode (clock-ticks), consumption
for this CPU in wait mode (clock-ticks), consumption for
this CPU in irq mode (clock-ticks), consumption for this
CPU in softirq mode (clock-ticks), consumption for this
CPU in steal mode (clock-ticks), consumption for this CPU
in guest mode (clock-ticks) overlapping user mode, fre‐
quency of all CPUs, frequency percentage of all CPUs, in‐
structions executed by all CPUs and cycles for all CPUs.
CPL Subsequent fields: number of processors, load average for
last minute, load average for last five minutes, load av‐
erage for last fifteen minutes, number of context-switch‐
es, and number of device interrupts.
GPU Subsequent fields: GPU number, bus-id string, type of GPU
string, GPU busy percentage during last second (-1 if not
available), memory busy percentage during last second (-1
if not available), total memory size (KiB), used memory
(KiB) at this moment, number of samples taken during in‐
terval, cumulative GPU busy percentage during the inter‐
val (to be divided by the number of samples for the aver‐
age busy percentage, -1 if not available), cumulative
memory busy percentage during the interval (to be divided
by the number of samples for the average busy percentage,
-1 if not available), and cumulative memory occupation
during the interval (to be divided by the number of sam‐
ples for the average occupation).
MEM Subsequent fields: page size for this machine (in bytes),
size of physical memory (pages), size of free memory
(pages), size of page cache (pages), size of buffer cache
(pages), size of slab (pages), dirty pages in cache
(pages), reclaimable part of slab (pages), total size of
vmware's balloon pages (pages), total size of shared mem‐
ory (pages), size of resident shared memory (pages), size
of swapped shared memory (pages), smaller huge page size
(in bytes), total size of smaller huge pages (huge
pages), size of free smaller huge pages (huge pages),
size of ARC (cache) of ZFSonlinux (pages), size of shar‐
ing pages for KSM (pages), size of shared pages for KSM
(pages), size of memory used for TCP sockets (pages),
size of memory used for UDP sockets (pages), size of
pagetables (pages), larger huge page size (in bytes), to‐
tal size of larger huge pages (huge pages), size of free
larger huge pages (huge pages), size of available memory
(pages) for new workloads without swapping, and size of
anonymous transparent huge pages ('normal' pages).
SWP Subsequent fields: page size for this machine (in bytes),
size of swap (pages), size of free swap (pages), size of
swap cache (pages), size of committed space (pages), lim‐
it for committed space (pages), size of the swap cache
(pages), the real (decompressed) size of the pages stored
in zswap (pages), and the size of compressed storage used
for zswap (pages).
LLC Subsequent fields: LLC id, percentage of LLC in use, to‐
tal memory bandwidth of this LLC (in bytes), and memory
bandwidth on local NUMA node of this LLC (in bytes).
PAG Subsequent fields: page size for this machine (in bytes),
number of page scans, number of allocstalls, 0 (future
use), number of swapins, number of swapouts, number of
oomkills (-1 when counter not present), number of process
stalls to run memory compaction, number of pages success‐
fully migrated in total, number of NUMA pages migrated,
number of pages read from block devices, number of pages
written to block devices, number of swapins from zswap,
and number of swapouts to zswap.
PSI Subsequent fields: PSI statistics present on this system
(n or y), CPU some avg10, CPU some avg60, CPU some
avg300, CPU some accumulated microseconds during inter‐
val, memory some avg10, memory some avg60, memory some
avg300, memory some accumulated microseconds during in‐
terval, memory full avg10, memory full avg60, memory full
avg300, memory full accumulated microseconds during in‐
terval, I/O some avg10, I/O some avg60, I/O some avg300,
I/O some accumulated microseconds during interval, I/O
full avg10, I/O full avg60, I/O full avg300, and I/O full
accumulated microseconds during interval.
LVM/MDD/DSK
For every logical volume/multiple device/hard disk one
line is shown.
Subsequent fields: name, number of milliseconds spent for
I/O, number of reads issued, number of sectors trans‐
ferred for reads, number of writes issued, number of sec‐
tors transferred for write, number of discards issued (-1
if not supported), number of sectors transferred for dis‐
cards, number of requests currently in flight (not yet
completed), and the average queue depth while the disk
was busy.
NFM Subsequent fields: mounted NFS filesystem, total number
of bytes read, total number of bytes written, number of
bytes read by normal system calls, number of bytes writ‐
ten by normal system calls, number of bytes read by di‐
rect I/O, number of bytes written by direct I/O, number
of pages read by memory-mapped I/O, and number of pages
written by memory-mapped I/O.
NFC Subsequent fields: number of transmitted RPCs, number of
transmitted read RPCs, number of transmitted write RPCs,
number of RPC retransmissions, and number of authoriza‐
tion refreshes.
NFS Subsequent fields: number of handled RPCs, number of re‐
ceived read RPCs, number of received write RPCs, number
of bytes read by clients, number of bytes written by
clients, number of RPCs with bad format, number of RPCs
with bad authorization, number of RPCs from bad client,
total number of handled network requests, number of han‐
dled network requests via TCP, number of handled network
requests via UDP, number of handled TCP connections, num‐
ber of hits on reply cache, number of misses on reply
cache, and number of uncached requests.
NET First, one line is produced for the upper layers of the
TCP/IP stack.
Subsequent fields: the verb "upper", number of packets
received by TCP, number of packets transmitted by TCP,
number of packets received by UDP, number of packets
transmitted by UDP, number of packets received by IP,
number of packets transmitted by IP, number of packets
delivered to higher layers by IP, number of packets for‐
warded by IP, number of input errors (UDP), number of no‐
port errors (UDP), number of active opens (TCP), number
of passive opens (TCP), number of passive opens (TCP),
number of established connections at this moment (TCP),
number of retransmitted segments (TCP), number of input
errors (TCP), number of output resets (TCP), and number
of checksum errors on received packets (TCP).
Next, one line is shown for every interface.
Subsequent fields: name of the interface, number of pack‐
ets received by the interface, number of bytes received
by the interface, number of packets transmitted by the
interface, number of bytes transmitted by the interface,
interface speed, and duplex mode (0=half, 1=full).
IFB Subsequent fields: name of the InfiniBand interface, port
number, number of lanes, maximum rate (Mbps), number of
bytes received, number of bytes transmitted, number of
packets received, and number of packets transmitted.
NUM Subsequent fields: NUMA node number, page size for this
machine (in bytes), the fragmentation percentage of this
node, size of physical memory (pages), size of free memo‐
ry (pages), recently (active) used memory (pages), less
recently (inactive) used memory (pages), size of cached
file data (pages), dirty pages in cache (pages), slab
memory being used for kernel mallocs (pages), slab memory
that is reclaimable (pages), shared memory including
tmpfs (pages), total huge pages (huge pages), and free
huge pages (huge pages).
NUC Subsequent fields: NUMA node number, number of processors
for this node, consumption for node CPUs in system mode
(clock-ticks), consumption for node CPUs in user mode
(clock-ticks), consumption for node CPUs in user mode for
niced processes (clock-ticks), consumption for node CPUs
in idle mode (clock-ticks), consumption for node CPUs in
wait mode (clock-ticks), consumption for node CPUs in irq
mode (clock-ticks), consumption for node CPUs in softirq
mode (clock-ticks), consumption for node CPUs in steal
mode (clock-ticks), and consumption for node CPUs in
guest mode (clock-ticks) overlapping user mode.
PRG For every process one line is shown.
Subsequent fields: PID (unique ID of task), name (between
parenthesis or underscores for spaces), state, real uid,
real gid, TGID (group number of related tasks/threads),
total number of threads, exit code (in case of fatal sig‐
nal: signal number + 256), start time (epoch), full com‐
mand line (between parenthesis or underscores for
spaces), PPID, number of threads in state 'running' (R),
number of threads in state 'interruptible sleeping' (S),
number of threads in state 'uninterruptible sleeping'
(D), effective uid, effective gid, saved uid, saved gid,
filesystem uid, filesystem gid, elapsed time of terminat‐
ed process (hertz), is_process (y/n), OpenVZ virtual pid
(VPID), OpenVZ container id (CTID), container/pod name
(CID/POD), indication if the task is newly started during
this interval ('N'), cgroup v2 path name (between paren‐
thesis or underscores for spaces), end time (epoch. or 0
if still active), and number of threads in state 'idle'
(I).
PRC For every process one line is shown.
Subsequent fields: PID, name (between parenthesis or un‐
derscores for spaces), state, total number of clock-ticks
per second for this machine, CPU-consumption in user mode
(clockticks), CPU-consumption in system mode (clock‐
ticks), nice value, priority, realtime priority, schedul‐
ing policy, current CPU, sleep average, TGID (group num‐
ber of related tasks/threads), is_process (y/n), runqueue
delay in nanoseconds for this thread or for all threads
(in case of process), wait channel of this thread (be‐
tween parenthesis or underscores for spaces), block I/O
delay (clockticks), number of voluntary context switches,
and number of involuntary context switches.
PRE For every process one line is shown.
Subsequent fields: PID, name (between parenthesis or un‐
derscores for spaces), process state, GPU state (A for
active, E for exited, N for no GPU user), number of GPUs
used by this process, bitlist reflecting used GPUs, GPU
busy percentage during interval, memory busy percentage
during interval, memory occupation (KiB) at this moment
cumulative memory occupation (KiB) during interval, and
number of samples taken during interval.
PRM For every process one line is shown.
Subsequent fields: PID, name (between parenthesis or un‐
derscores for spaces), state, page size for this machine
(in bytes), virtual memory size (Kbytes), resident memory
size (Kbytes), shared text memory size (Kbytes), virtual
memory growth (Kbytes), resident memory growth (Kbytes),
number of minor page faults, number of major page faults,
virtual library exec size (Kbytes), virtual data size
(Kbytes), virtual stack size (Kbytes), swap space used
(Kbytes), TGID (group number of related tasks/threads),
is_process (y/n), proportional set size (Kbytes) if in
'R' option is specified and virtually locked memory space
(Kbytes).
PRD For every process one line is shown.
Subsequent fields: PID, name (between parenthesis or un‐
derscores for spaces), state, obsoleted kernel patch in‐
stalled ('n'), standard io statistics used ('y' or 'n'),
number of reads on disk, cumulative number of sectors
read, number of writes on disk, cumulative number of sec‐
tors written, cancelled number of written sectors, TGID
(group number of related tasks/threads), obsoleted value
('n'), and is_process (y/n).
PRN For every process one line is shown.
Subsequent fields: PID, name (between parenthesis or un‐
derscores for spaces), state, pmdabpf(1) or pmdabcc(1)
module 'netproc' loaded ('y' or 'n'), number of
tcp_sendmsg() calls, cumulative size of TCP buffers re‐
quested to be transmitted, number of
tcp_recvmsg()/tcp_cleanup_rbuf() calls, cumulative size
of TCP buffers received, number of udp_sendmsg() calls,
cumulative size of UDP buffers requested to be transmit‐
ted, number of udp_recvmsg()/skb_consume_udp() calls, cu‐
mulative size of UDP buffers transmitted, number of raw
packets transmitted (obsolete, always 0), number of raw
packets received (obsolete, always 0), TGID (group number
of related tasks/threads) and is_process (y/n).
By sending the SIGUSR1 signal to pcp-atop a new sample will be
forced, even if the current timer interval has not exceeded yet.
The behavior is similar to pressing the 't' key in an interactive
session.
By sending the SIGUSR2 signal to pcp-atop a final sample will be
forced after which pcp-atop will terminate.
To monitor the current system load interactively with an interval
of (default) 10 seconds:
pcp atop
To monitor the system load as bar graphs with an interval of 5
seconds:
pcp atop -B 5
Store information about the system and process activity in a PCP
archive folio with an interval of ten minutes during an hour:
pcp atop -w /tmp/pcp-atop 600 6
View the contents of this file interactively:
pcp atop -r /tmp/pcp-atop
View the processor and disk utilization of this file in parsable
format:
pcp atop -PCPU,DSK -r /tmp/pcp-atop.folio
View the contents of today's standard logfile interactively:
pcp atop -r
View the contents of the standard logfile of the day before yes‐
terday interactively:
pcp atop -r yy
View the contents of the standard logfile of 2023, June 7 from
02:00 PM onwards interactively:
pcp atop -r 20230607 -b 14:00
To monitor the system load and write it to a file (in plain ASCII)
with an interval of one minute during half an hour with active
processes sorted on memory consumption:
pcp atop -M 60 30 > /log/pcp-atop.mem
pcp-atop is based on the source code of the atop(1) command from
https://atoptool.nl , maintained by Gerlof Langeveld
([email protected]), and aims to be command line and
output compatible with it as much as possible.
Some features of pcp-atop (such as reporting on the Apache HTTP
daemon, Infiniband, NFS client mounts, hardware event counts, GPU
statistics and per-process TCP and UDP statistics) are only acti‐
vated if the corresponding PCP metrics are available. Refer to the
documentation for pmdaapache(1), pmdainfiniband(1),
pmdanfsclient(1), pmdanvidia(1), pmdaperfevent(1) pmdabcc(1) and
pmdabpf(1) for further details on activating these metrics.
The semantics of the per-process network statistics deviate
slightly from the atop(1) tool: instead of the number of TCP/UDP
packets sent/received (which may be inaccurate due to TCP segmen‐
tation offload), pcp-atop shows the number of
tcp_sendmsg()/udp_sendmsg()/etc. kernel calls per process.
/etc/atoprc
Configuration file containing system-wide default values.
For further information about the default values, refer to
the pcp-atoprc(5) man page).
~/.atoprc
Configuration file containing personal default values. For
further information about the default values, refer to the
pcp-atoprc(5) man page).
Environment variables with the prefix PCP_ are used to parameter‐
ize the file and directory names used by PCP. On each installa‐
tion, the file /etc/pcp.conf contains the local values for these
variables. The $PCP_CONF variable may be used to specify an al‐
ternative configuration file, as described in pcp.conf(5).
For environment variables affecting PCP tools, see
pmGetOptions(3).
The -D or --debug pcp option enables the output of additional di‐
agnostics on stderr to help triage problems, although the informa‐
tion is sometimes cryptic and primarily intended to provide guid‐
ance for developers rather end-users. debug is a comma separated
list of debugging options; use pmdbg(1) with the -l option to ob‐
tain a list of the available debugging options and their meaning.
Debugging options specific to pcp-atop are as follows:
┌────────┬───────────────────────────────────────┐
│ Option │ Description │
├────────┼───────────────────────────────────────┤
│ appl0 │ general diagnostics │
├────────┼───────────────────────────────────────┤
│ appl1 │ metric and instance domain retrievals │
└────────┴───────────────────────────────────────┘
PCPIntro(1), pcp(1), pcp-atopsar(1), pmdaapache(1), pmdabcc(1),
pmdabpf(1), pmdainfiniband(1), pmdanfsclient(1), pmdanvidia(1),
pmdaproc(1), mkaf(1), pmlogger(1), pmlogger_daily(1) and
pcp-atoprc(5).
This page is part of the PCP (Performance Co-Pilot) project. In‐
formation about the project can be found at ⟨http://www.pcp.io/⟩.
If you have a bug report for this manual page, send it to
[email protected]. This page was obtained from the project's upstream
Git repository ⟨https://github.com/performancecopilot/pcp.git⟩ on
2025-08-11. (At that time, the date of the most recent commit
that was found in the repository was 2025-08-11.) If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page,
or you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a
mail to [email protected]
Performance Co-Pilot PCP PCP-ATOP(1)
Pages that refer to this page: pcp-atopsar(1), pmafm(1), pmdaamdgpu(1), pmdanvidia(1), pmrep(1), pcp-atoprc(5)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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