From: Christian Ehrhardt Date: Fri, 10 Mar 2006 01:33:49 +0000 (-0800) Subject: [PATCH] s390: Increase spinlock retry code performance X-Git-Tag: v2.6.16-rc6~35 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=96567161de0ceed45cd2eb0e5380e3c797f5c0f4;p=pandora-kernel.git [PATCH] s390: Increase spinlock retry code performance Currently the code tries up to spin_retry times to grab a lock using the cs instruction. The cs instruction has exclusive access to a memory region and therefore invalidates the appropiate cache line of all other cpus. If there is contention on a lock this leads to cache line trashing. This can be avoided if we first check wether a cs instruction is likely to succeed before the instruction gets actually executed. Signed-off-by: Christian Ehrhardt Signed-off-by: Martin Schwidefsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed