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| author | jeff <jeff@FreeBSD.org> | 2002-03-12 04:00:11 +0000 |
|---|---|---|
| committer | jeff <jeff@FreeBSD.org> | 2002-03-12 04:00:11 +0000 |
| commit | e6d26e8880ff741e6a936a20fbcab7c5df6443c0 (patch) | |
| tree | db3ad14ad172419e9392e38ccefc609f619092d3 /sys/conf | |
| parent | b6412800f5692591eb5568403f073bc55cc762ff (diff) | |
| download | FreeBSD-src-e6d26e8880ff741e6a936a20fbcab7c5df6443c0.zip FreeBSD-src-e6d26e8880ff741e6a936a20fbcab7c5df6443c0.tar.gz | |
This patch adds the "LOCKSHARED" option to namei which causes it to only acquire shared locks on leafs.
The stat() and open() calls have been changed to make use of this new functionality. Using shared locks in
these cases is sufficient and can significantly reduce their latency if IO is pending to these vnodes. Also,
this reduces the number of exclusive locks that are floating around in the system, which helps reduce the
number of deadlocks that occur.
A new kernel option "LOOKUP_SHARED" has been added. It defaults to off so this patch can be turned on for
testing, and should eventually go away once it is proven to be stable. I have personally been running this
patch for over a year now, so it is believed to be fully stable.
Reviewed by: jake, obrien
Approved by: jake
Diffstat (limited to 'sys/conf')
| -rw-r--r-- | sys/conf/options | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/sys/conf/options b/sys/conf/options index c3101df..fede7fd 100644 --- a/sys/conf/options +++ b/sys/conf/options @@ -383,6 +383,7 @@ BLKDEV_IOSIZE opt_global.h DEBUG opt_global.h DEBUG_LOCKS opt_global.h DEBUG_VFS_LOCKS opt_global.h +LOOKUP_SHARED opt_global.h DIAGNOSTIC opt_global.h ENABLE_VFS_IOOPT opt_global.h INVARIANT_SUPPORT opt_global.h |
