Commits
Minchan Kim committed 9cb937e2195
mm, page_alloc: fix dirtyable highmem calculation
When I tested vmscale in mmtest in 32bit, I found the benchmark was slow
down 0.5 times.
base node
1 global-1
User 12.98 16.04
System 147.61 166.42
Elapsed 26.48 38.08
With vmstat, I found IO wait avg is much increased compared to base.
The reason was highmem_dirtyable_memory accumulates free pages and
highmem_file_pages from HIGHMEM to MOVABLE zones which was wrong. With
that, dirth_thresh in throtlle_vm_write is always 0 so that it calls
congestion_wait frequently if writeback starts.
With this patch, it is much recovered.
base node fi
1 global-1 fix
User 12.98 16.04 13.78
System 147.61 166.42 143.92
Elapsed 26.48 38.08 29.64
Link: http://lkml.kernel.org/r/1468404004-5085-4-git-send-email-mgorman@techsingularity.net
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>