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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-19 18:59:47 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-05-19 18:59:47 -0700 |
commit | 044aea9b83614948c98564000db07d1d32b2d29b (patch) | |
tree | b1f13ed2f4bb0bd40f7915a89aafaf449b6145cd /drivers/target | |
parent | 39ab05c8e0b519ff0a04a869f065746e6e8c3d95 (diff) | |
download | op-kernel-dev-044aea9b83614948c98564000db07d1d32b2d29b.zip op-kernel-dev-044aea9b83614948c98564000db07d1d32b2d29b.tar.gz |
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 <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/target')
0 files changed, 0 insertions, 0 deletions