From: Eric Dumazet Date: Tue, 3 Apr 2012 05:28:28 +0000 (+0000) Subject: af_unix: reduce high order page allocations X-Git-Tag: v3.5-rc1~109^2~662 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eb6a24816b247c;p=pandora-kernel.git af_unix: reduce high order page allocations unix_dgram_sendmsg() currently builds linear skbs, and this can stress page allocator with high order page allocations. When memory gets fragmented, this can eventually fail. We can try to use order-2 allocations for skb head (SKB_MAX_ALLOC) plus up to 16 page fragments to lower pressure on buddy allocator. This patch has no effect on messages of less than 16064 bytes. (on 64bit arches with PAGE_SIZE=4096) For bigger messages (from 16065 to 81600 bytes), this patch brings reliability at the expense of performance penalty because of extra pages allocations. netperf -t DG_STREAM -T 0,2 -- -m 16064 -s 200000 ->4086040 Messages / 10s netperf -t DG_STREAM -T 0,2 -- -m 16068 -s 200000 ->3901747 Messages / 10s Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- Reading git-diff-tree failed