From 93a05e65c090dda9cbd79d0cf57b65c4dbd8da55 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 13 May 2010 12:51:06 -0400 Subject: SUNRPC: Ensure memory shrinker doesn't waste time in rpcauth_prune_expired() The 'cred_unused' list, that is traversed by rpcauth_cache_shrinker is ordered by time. If we hit a credential that is under the 60 second garbage collection moratorium, we should exit because we know at that point that all successive credentials are subject to the same moratorium... Signed-off-by: Trond Myklebust --- net/sunrpc/auth.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'net/sunrpc') diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index 0667a36aee78..c40856f589f0 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -236,10 +236,13 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan) list_for_each_entry_safe(cred, next, &cred_unused, cr_lru) { - /* Enforce a 60 second garbage collection moratorium */ + /* + * Enforce a 60 second garbage collection moratorium + * Note that the cred_unused list must be time-ordered. + */ if (time_in_range(cred->cr_expire, expired, jiffies) && test_bit(RPCAUTH_CRED_HASHED, &cred->cr_flags) != 0) - continue; + return 0; list_del_init(&cred->cr_lru); number_cred_unused--; @@ -258,7 +261,7 @@ rpcauth_prune_expired(struct list_head *free, int nr_to_scan) if (nr_to_scan == 0) break; } - return nr_to_scan; + return (number_cred_unused / 100) * sysctl_vfs_cache_pressure; } /* @@ -275,8 +278,7 @@ rpcauth_cache_shrinker(int nr_to_scan, gfp_t gfp_mask) if (list_empty(&cred_unused)) return 0; spin_lock(&rpc_credcache_lock); - nr_to_scan = rpcauth_prune_expired(&free, nr_to_scan); - res = (number_cred_unused / 100) * sysctl_vfs_cache_pressure; + res = rpcauth_prune_expired(&free, nr_to_scan); spin_unlock(&rpc_credcache_lock); rpcauth_destroy_credlist(&free); return res; -- cgit v1.2.3