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author | Dmitry Kasatkin <dmitry.kasatkin@intel.com> | 2012-02-08 14:15:42 -0500 |
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committer | Mimi Zohar <zohar@linux.vnet.ibm.com> | 2012-09-07 14:57:46 -0400 |
commit | a10bf26b2f53242836e9362c6c9c857b627b82a9 (patch) | |
tree | 98c7b83684f1df42571013af4c0572c7eeea8e76 /scripts/mod/Makefile | |
parent | bf2276d10ce58ff44ab8857266a6718024496af6 (diff) | |
download | op-kernel-dev-a10bf26b2f53242836e9362c6c9c857b627b82a9.zip op-kernel-dev-a10bf26b2f53242836e9362c6c9c857b627b82a9.tar.gz |
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>
Diffstat (limited to 'scripts/mod/Makefile')
0 files changed, 0 insertions, 0 deletions