From 8066a14a3c412e1a7d9e3816fa3500cc51fa5937 Mon Sep 17 00:00:00 2001 From: Mateusz Guzik Date: Thu, 4 May 2017 03:11:59 +0000 Subject: [PATCH] cache: stop holding the ncneg_hot lock across purging Only non-hot entries are purged so the lock is not needed in the first place. This saves one lock/unlock pair. MFC after: 1 week --- sys/kern/vfs_cache.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c index b9507c0239e..5dc4636b3d7 100644 --- a/sys/kern/vfs_cache.c +++ b/sys/kern/vfs_cache.c @@ -735,13 +735,12 @@ cache_negative_remove(struct namecache *ncp, bool neg_locked) list_locked = true; mtx_lock(&neglist->nl_lock); } - } else { - mtx_assert(&neglist->nl_lock, MA_OWNED); - mtx_assert(&ncneg_hot.nl_lock, MA_OWNED); } if (ncp->nc_flag & NCF_HOTNEGATIVE) { + mtx_assert(&ncneg_hot.nl_lock, MA_OWNED); TAILQ_REMOVE(&ncneg_hot.nl_list, ncp, nc_dst); } else { + mtx_assert(&neglist->nl_lock, MA_OWNED); TAILQ_REMOVE(&neglist->nl_list, ncp, nc_dst); } if (list_locked) @@ -816,7 +815,6 @@ cache_negative_zap_one(void) mtx_unlock(&ncneg_hot.nl_lock); mtx_lock(dvlp); rw_wlock(blp); - mtx_lock(&ncneg_hot.nl_lock); mtx_lock(&neglist->nl_lock); ncp2 = TAILQ_FIRST(&neglist->nl_list); if (ncp != ncp2 || dvlp != VP2VNODELOCK(ncp2->nc_dvp) || @@ -830,7 +828,6 @@ cache_negative_zap_one(void) cache_zap_locked(ncp, true); out_unlock_all: mtx_unlock(&neglist->nl_lock); - mtx_unlock(&ncneg_hot.nl_lock); rw_wunlock(blp); mtx_unlock(dvlp); out: