From eb59254608bc1d42c4c6afdcdce9c0d3ce02b318 Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Tue, 10 Apr 2018 16:27:36 -0700 Subject: [PATCH] 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 Reviewed-by: Andrew Morton Cc: Alexander Viro Cc: Michal Hocko Cc: Johannes Weiner Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mmzone.h | 1 + mm/vmstat.c | 1 + 2 files changed, 2 insertions(+) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index f11ae29005f1..a0c9e45a859a 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -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 }; diff --git a/mm/vmstat.c b/mm/vmstat.c index 33581be705f0..536332e988b8 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -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",