Commit eb592546 authored Apr 10, 2018 by Roman Gushchin Committed by Linus Torvalds Apr 11, 2018

mm: introduce NR_INDIRECTLY_RECLAIMABLE_BYTES

Patch series "indirectly reclaimable memory", v2.

This patchset introduces the concept of indirectly reclaimable memory
and applies it to fix the issue of when a big number of dentries with
external names can significantly affect the MemAvailable value.

This patch (of 3):

Introduce a concept of indirectly reclaimable memory and adds the
corresponding memory counter and /proc/vmstat item.

Indirectly reclaimable memory is any sort of memory, used by the kernel
(except of reclaimable slabs), which is actually reclaimable, i.e.  will
be released under memory pressure.

The counter is in bytes, as it's not always possible to count such
objects in pages.  The name contains BYTES by analogy to
NR_KERNEL_STACK_KB.

Link: http://lkml.kernel.org/r/20180305133743.12746-2-guro@fb.com


Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent f77cfbe6

include/linux/mmzone.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -180,6 +180,7 @@ enum node_stat_item {
		NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
		NR_DIRTIED, /* page dirtyings since bootup */
		NR_WRITTEN, /* page writings since bootup */
		NR_INDIRECTLY_RECLAIMABLE_BYTES, /* measured in bytes */
		NR_VM_NODE_STAT_ITEMS
		};

mm/vmstat.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -1161,6 +1161,7 @@ const char * const vmstat_text[] = {
		"nr_vmscan_immediate_reclaim",
		"nr_dirtied",
		"nr_written",
		"nr_indirectly_reclaimable",

		/* enum writeback_stat_item counters */
		"nr_dirty_threshold",

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