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Groups > linux.kernel > #1280241
| From | Johannes Weiner <hannes@cmpxchg.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 2/2] proc: meminfo: estimate available memory more conservatively |
| Date | 2015-11-30 21:10 +0100 |
| Message-ID | <qACVP-8dD-5@gated-at.bofh.it> (permalink) |
| References | <qACVP-8dD-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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@cmpxchg.org> --- fs/proc/meminfo.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c index 9155a5a..df4661a 100644 --- a/fs/proc/meminfo.c +++ b/fs/proc/meminfo.c @@ -57,11 +57,8 @@ static int meminfo_proc_show(struct seq_file *m, void *v) /* * 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 -- 2.6.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH 2/2] proc: meminfo: estimate available memory more conservatively Johannes Weiner <hannes@cmpxchg.org> - 2015-11-30 21:10 +0100 Re: [PATCH 2/2] proc: meminfo: estimate available memory more conservatively Michal Hocko <mhocko@kernel.org> - 2015-12-03 17:50 +0100
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