From: Dmitry Kasatkin Date: Wed, 8 Feb 2012 19:15:42 +0000 (-0500) Subject: ima: replace iint spinblock with rwlock/read_lock X-Git-Tag: omap-for-v3.7-rc1/fixes-cpufreq-signed~32^2~11^2~4 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a10bf26b2f53242836e9362c6c9c857b627b82a9;p=pandora-kernel.git ima: replace iint spinblock with rwlock/read_lock For performance, replace the iint spinlock with rwlock/read_lock. Eric Paris questioned this change, from spinlocks to rwlocks, saying "rwlocks have been shown to actually be slower on multi processor systems in a number of cases due to the cache line bouncing required." Based on performance measurements compiling the kernel on a cold boot with multiple jobs with/without this patch, Dmitry Kasatkin and I found that rwlocks performed better than spinlocks, but very insignificantly. For example with total compilation time around 6 minutes, with rwlocks time was 1 - 3 seconds shorter... but always like that. Changelog v2: - new patch taken from the 'allocating iint improvements' patch Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- Reading git-diff-tree failed