From: Linus Torvalds Date: Fri, 20 May 2011 01:59:47 +0000 (-0700) Subject: selinux: de-crapify avc cache stat code generation X-Git-Tag: v3.0-rc1~389 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=044aea9b83614948c98564000db07d1d32b2d29b;p=pandora-kernel.git selinux: de-crapify avc cache stat code generation You can turn off the avc cache stats, but distributions seem to not do that (perhaps because several performance tuning how-to's talk about the avc cache statistics). Which is sad, because the code it generates is truly horrendous, with the statistics update being sandwitched between get_cpu/put_cpu which in turn causes preemption disables etc. We're talking ten+ instructions just to increment a per-cpu variable in some pretty hot code. Fix the craziness by just using 'this_cpu_inc()' instead. Suddenly we only need a single 'inc' instruction to increment the statistics. This is quite noticeable in the incredibly hot avc_has_perm_noaudit() function (which triggers all the statistics by virtue of doing an avc_lookup() call). Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed