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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | NOTES | PCP ENVIRONMENT | SEE ALSO | COLOPHON |
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PCP-BUDDYINFO(1) General Commands Manual PCP-BUDDYINFO(1)
pcp-buddyinfo - report Linux kernel buddy algorithm statistics
pcp [pcp options] buddyinfo [-uVz?] [-s samples] [-a archive] [-Z
timezone]
The pcp-buddyinfo command is used for viewing different stats
related to buddyinfo. It helps users analyze the dynamic
behaviour of the buddy algorithm used in the Linux kernel virtual
memory subsystem. The information includes the total number of
zones that are currently active, counts of different order pages,
and so on. By default, pcp-buddyinfo reports live data for the
local host.
The statistics shown are as follows:
HEADER DESCRIPTION
_ _
Normal zones available
Nodes available nodes
Order0 available pages of order 0
Order1 available pages of order 1
Order2 available pages of order 2
Order3 available pages of order 3
Order4 available pages of order 4
Order5 available pages of order 5
Order6 available pages of order 6
Order7 available pages of order 7
Order8 available pages of order 8
Order9 available pages of order 9
Order10 available pages of order 10
Each column represents the number of pages of a certain order (a
certain size) that are available at any given time. For example,
for zone DMA (direct memory access), there are 90 of
2^(0*PAGE_SIZE) chunks of memory. Similarly, there are 6 of
2^(1*PAGE_SIZE) chunks, and 2 of 2^(2*PAGE_SIZE) chunks of memory
available.
The DMA row references the first 16 MB on a system, the HighMem
row references all memory greater than 4 GB on a system, and the
Normal row references all memory in between.
-a file, --archive=file
Fetch buddyinfo metrics from the specified PCP archive.
-s count, --samples=count
Limit reporting to count samples of buddyinfo statistics.
-u, --no-interpol
disable the default interpolation mode when replaying an
archive. With the -u option, interpolated reporting is
disabled and each sample is reported according to native
sampling intervals in the archive. In this mode the -t
option is ignored. Additionally, non-interpolated replay
makes sense only when replaying an archive (using the -a
option described above), so the -a option is mandatory when
-u is specified.
-z, --hostzone
Use the local timezone of the host that is the source of
the performance metrics, as identified by either the -h or
the -a options. The default is to use the timezone of the
local host.
-Z timezone, --timezone=timezone
Use timezone for the date and time. Timezone is in the
format of the environment variable TZ as described in
environ(7).
-V, --version
Display version number and exit.
-?, --help
Display usage message and exit.
pcp-buddyinfo reports information extracted from the
/proc/buddyinfo Linux kernel procfs file.
If the default interpolation mode is disabled, it is possible that
some metrics (recorded at different intervals) will be reported as
having missing values for some samples even if they were recorded.
Environment variables with the prefix PCP_ are used to
parameterize the file and directory names used by PCP. On each
installation, the file /etc/pcp.conf contains the local values for
these variables. The $PCP_CONF variable may be used to specify an
alternative configuration file, as described in pcp.conf(5).
For environment variables affecting PCP tools, see
pmGetOptions(3).
PCPIntro(1), pcp(1), pmGetOptions(3), pcp.conf(5) and environ(7).
This page is part of the PCP (Performance Co-Pilot) project.
Information 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-BUDDYINFO(1)
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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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