Seth Jennings 3d65c85f91 staging: zcache: reduce tmem bucket lock contention ... tmem uses hash buckets each with their own rbtree and lock to quickly lookup tmem objects. tmem has TMEM_HASH_BUCKETS (256) buckets per pool. However, because of the way the tmem_oid is generated for frontswap pages, only 16 unique tmem_oids are being generated, resulting in only 16 of the 256 buckets being used. This cause high lock contention for the per bucket locks. This patch changes SWIZ_BITS to include more bits of the offset. The result is that all 256 hash buckets are potentially used resulting in a 95% drop in hash bucket lock contention. Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>		2011-10-12 09:29:03 -06:00
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Kconfig	staging: zcache: misc build/config	2011-02-09 15:08:22 -08:00
Makefile	staging: fix zcache building	2011-08-02 16:06:18 -07:00
tmem.c	Staging: zcache: signedness bug in tmem_get()	2011-08-23 14:52:20 -07:00
tmem.h	staging: zcache: support multiple clients, prep for KVM and RAMster	2011-07-08 14:18:53 -07:00
zcache-main.c	staging: zcache: reduce tmem bucket lock contention	2011-10-12 09:29:03 -06:00