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authorRik van Riel <riel@redhat.com>2012-03-22 03:33:52 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-22 04:54:56 +0400
commit7be62de99adcab4449d416977b4274985c5fe023 (patch)
tree20ae021ec9811ad730e6a17a3530d3aa6b5027d0 /include/linux/compaction.h
parentfe2c2a106663130a5ab45cb0e3414b52df2fff0c (diff)
downloadlinux-7be62de99adcab4449d416977b4274985c5fe023.tar.xz
vmscan: kswapd carefully call compaction
With CONFIG_COMPACTION enabled, kswapd does not try to free contiguous free pages, even when it is woken for a higher order request. This could be bad for eg. jumbo frame network allocations, which are done from interrupt context and cannot compact memory themselves. Higher than before allocation failure rates in the network receive path have been observed in kernels with compaction enabled. Teach kswapd to defragment the memory zones in a node, but only if required and compaction is not deferred in a zone. [akpm@linux-foundation.org: reduce scope of zones_need_compaction] Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/compaction.h')
-rw-r--r--include/linux/compaction.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index bb2bbdbe5464..7a9323aef4a3 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -23,6 +23,7 @@ extern int fragmentation_index(struct zone *zone, unsigned int order);
extern unsigned long try_to_compact_pages(struct zonelist *zonelist,
int order, gfp_t gfp_mask, nodemask_t *mask,
bool sync);
+extern int compact_pgdat(pg_data_t *pgdat, int order);
extern unsigned long compaction_suitable(struct zone *zone, int order);
/* Do not skip compaction more than 64 times */
@@ -62,6 +63,11 @@ static inline unsigned long try_to_compact_pages(struct zonelist *zonelist,
return COMPACT_CONTINUE;
}
+static inline int compact_pgdat(pg_data_t *pgdat, int order)
+{
+ return COMPACT_CONTINUE;
+}
+
static inline unsigned long compaction_suitable(struct zone *zone, int order)
{
return COMPACT_SKIPPED;