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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:43:11 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:43:11 +0000 |
commit | fc22b3d6507c6745911b9dfcc68f1e665ae13dbc (patch) | |
tree | ce1e3bce06471410239a6f41282e328770aa404a /upstream/archlinux/man5/proc_buddyinfo.5 | |
parent | Initial commit. (diff) | |
download | manpages-l10n-fc22b3d6507c6745911b9dfcc68f1e665ae13dbc.tar.xz manpages-l10n-fc22b3d6507c6745911b9dfcc68f1e665ae13dbc.zip |
Adding upstream version 4.22.0.upstream/4.22.0
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'upstream/archlinux/man5/proc_buddyinfo.5')
-rw-r--r-- | upstream/archlinux/man5/proc_buddyinfo.5 | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/upstream/archlinux/man5/proc_buddyinfo.5 b/upstream/archlinux/man5/proc_buddyinfo.5 new file mode 100644 index 00000000..7b3db6c6 --- /dev/null +++ b/upstream/archlinux/man5/proc_buddyinfo.5 @@ -0,0 +1,58 @@ +.\" Copyright (C) 1994, 1995, Daniel Quinlan <quinlan@yggdrasil.com> +.\" Copyright (C) 2002-2008, 2017, Michael Kerrisk <mtk.manpages@gmail.com> +.\" Copyright (C) 2023, Alejandro Colomar <alx@kernel.org> +.\" +.\" SPDX-License-Identifier: GPL-3.0-or-later +.\" +.TH proc_buddyinfo 5 2023-08-15 "Linux man-pages 6.06" +.SH NAME +/proc/buddyinfo \- memory fragmentation +.SH DESCRIPTION +.TP +.I /proc/buddyinfo +This file contains information which is used for diagnosing memory +fragmentation issues. +Each line starts with the identification of the node and the name +of the zone which together identify a memory region. +This is then +followed by the count of available chunks of a certain order in +which these zones are split. +The size in bytes of a certain order is given by the formula: +.IP +.in +4n +.EX +(2\[ha]order)\ *\ PAGE_SIZE +.EE +.in +.IP +The binary buddy allocator algorithm inside the kernel will split +one chunk into two chunks of a smaller order (thus with half the +size) or combine two contiguous chunks into one larger chunk of +a higher order (thus with double the size) to satisfy allocation +requests and to counter memory fragmentation. +The order matches the column number, when starting to count at zero. +.IP +For example on an x86-64 system: +.RS -12 +.EX +Node 0, zone DMA 1 1 1 0 2 1 1 0 1 1 3 +Node 0, zone DMA32 65 47 4 81 52 28 13 10 5 1 404 +Node 0, zone Normal 216 55 189 101 84 38 37 27 5 3 587 +.EE +.RE +.IP +In this example, there is one node containing three zones and there +are 11 different chunk sizes. +If the page size is 4 kilobytes, then the first zone called +.I DMA +(on x86 the first 16 megabyte of memory) has 1 chunk of 4 kilobytes +(order 0) available and has 3 chunks of 4 megabytes (order 10) available. +.IP +If the memory is heavily fragmented, the counters for higher +order chunks will be zero and allocation of large contiguous areas +will fail. +.IP +Further information about the zones can be found in +.IR /proc/zoneinfo . +.SH SEE ALSO +.BR proc (5) |