This patch converts the underlying lock in rename_lock from spinlock to a read/write lock. This allows multiple blocking readers to proceed concurrently which is not possible with a spinlock implementation.
As contention of the rename_lock in the d_path() function is a bottleneck when the perf tool is used to record performance data on a large SMP system with many cores, converting rename_lock to use read/write lock will eliminate this bottleneck and the skewing of perf trace data. Signed-off-by: Waiman Long <[email protected]> --- fs/dcache.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index 480c81f..75299cc 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -82,7 +82,7 @@ int sysctl_vfs_cache_pressure __read_mostly = 100; EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure); static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock); -__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock); +__cacheline_aligned_in_smp DEFINE_SEQRWLOCK(rename_lock); EXPORT_SYMBOL(rename_lock); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
