The patch titled
Subject: proc: meminfo: estimate available memory more conservatively
has been added to the -mm tree. Its filename is
proc-meminfo-estimate-available-memory-more-conservatively.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/proc-meminfo-estimate-available-memory-more-conservatively.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/proc-meminfo-estimate-available-memory-more-conservatively.patch
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------------------------------------------------------
From: Johannes Weiner <hannes@xxxxxxxxxxx>
Subject: proc: meminfo: estimate available memory more conservatively
The MemAvailable item in /proc/meminfo is to give users a hint of how much
memory is allocatable without causing swapping, so it excludes the zones'
low watermarks as unavailable to userspace.
However, for a userspace allocation, kswapd will actually reclaim until
the free pages hit a combination of the high watermark and the page
allocator's lowmem protection that keeps a certain amount of DMA and DMA32
memory from userspace as well.
Subtract the full amount we know to be unavailable to userspace from the
number of free pages when calculating MemAvailable.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/meminfo.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff -puN fs/proc/meminfo.c~proc-meminfo-estimate-available-memory-more-conservatively fs/proc/meminfo.c
--- a/fs/proc/meminfo.c~proc-meminfo-estimate-available-memory-more-conservatively
+++ a/fs/proc/meminfo.c
@@ -57,11 +57,8 @@ static int meminfo_proc_show(struct seq_
/*
* Estimate the amount of memory available for userspace allocations,
* without causing swapping.
- *
- * Free memory cannot be taken below the low watermark, before the
- * system starts swapping.
*/
- available = i.freeram - wmark_low;
+ available = i.freeram - totalreserve_pages;
/*
* Not all the page cache can be freed, otherwise the system will
_
Patches currently in -mm which might be from hannes@xxxxxxxxxxx are
maintainers-make-vladimir-co-maintainer-of-the-memory-controller.patch
mm-page_alloc-generalize-the-dirty-balance-reserve.patch
proc-meminfo-estimate-available-memory-more-conservatively.patch
mm-increase-swap_cluster_max-to-batch-tlb-flushes-fix.patch
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