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linux/security/integrity
Dmitry Kasatkin a10bf26b2f 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 <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2012-09-07 14:57:46 -04:00
..
evm ima: integrity appraisal extension 2012-09-07 14:57:44 -04:00
ima ima: allocating iint improvements 2012-09-07 14:57:45 -04:00
digsig.c integrity: digital signature verification using multiple keyrings 2011-11-09 16:51:09 +02:00
iint.c ima: replace iint spinblock with rwlock/read_lock 2012-09-07 14:57:46 -04:00
integrity.h ima: integrity appraisal extension 2012-09-07 14:57:44 -04:00
Kconfig integrity: digital signature config option name change 2012-01-18 10:46:27 +11:00
Makefile integrity: digital signature config option name change 2012-01-18 10:46:27 +11:00