Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760517AbaGDWWX (ORCPT ); Fri, 4 Jul 2014 18:22:23 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:57642 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753661AbaGDWWT (ORCPT ); Fri, 4 Jul 2014 18:22:19 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeff Layton , "J. Bruce Fields" Subject: [PATCH 3.10 27/46] nfsd: dont try to reuse an expired DRC entry off the list Date: Fri, 4 Jul 2014 15:19:31 -0700 Message-Id: <20140704221603.515056385@linuxfoundation.org> X-Mailer: git-send-email 2.0.1 In-Reply-To: <20140704221602.280733370@linuxfoundation.org> References: <20140704221602.280733370@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeff Layton commit a0ef5e19684f0447da9ff0654a12019c484f57ca upstream. Currently when we are processing a request, we try to scrape an expired or over-limit entry off the list in preference to allocating a new one from the slab. This is unnecessarily complicated. Just use the slab layer. Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfscache.c | 36 ++++-------------------------------- 1 file changed, 4 insertions(+), 32 deletions(-) --- a/fs/nfsd/nfscache.c +++ b/fs/nfsd/nfscache.c @@ -129,13 +129,6 @@ nfsd_reply_cache_alloc(void) } static void -nfsd_reply_cache_unhash(struct svc_cacherep *rp) -{ - hlist_del_init(&rp->c_hash); - list_del_init(&rp->c_lru); -} - -static void nfsd_reply_cache_free_locked(struct svc_cacherep *rp) { if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base) { @@ -402,22 +395,8 @@ nfsd_cache_lookup(struct svc_rqst *rqstp /* * Since the common case is a cache miss followed by an insert, - * preallocate an entry. First, try to reuse the first entry on the LRU - * if it works, then go ahead and prune the LRU list. + * preallocate an entry. */ - spin_lock(&cache_lock); - if (!list_empty(&lru_head)) { - rp = list_first_entry(&lru_head, struct svc_cacherep, c_lru); - if (nfsd_cache_entry_expired(rp) || - num_drc_entries >= max_drc_entries) { - nfsd_reply_cache_unhash(rp); - prune_cache_entries(); - goto search_cache; - } - } - - /* No expired ones available, allocate a new one. */ - spin_unlock(&cache_lock); rp = nfsd_reply_cache_alloc(); spin_lock(&cache_lock); if (likely(rp)) { @@ -425,7 +404,9 @@ nfsd_cache_lookup(struct svc_rqst *rqstp drc_mem_usage += sizeof(*rp); } -search_cache: + /* go ahead and prune the cache */ + prune_cache_entries(); + found = nfsd_cache_search(rqstp, csum); if (found) { if (likely(rp)) @@ -439,15 +420,6 @@ search_cache: goto out; } - /* - * We're keeping the one we just allocated. Are we now over the - * limit? Prune one off the tip of the LRU in trade for the one we - * just allocated if so. - */ - if (num_drc_entries >= max_drc_entries) - nfsd_reply_cache_free_locked(list_first_entry(&lru_head, - struct svc_cacherep, c_lru)); - nfsdstats.rcmisses++; rqstp->rq_cacherep = rp; rp->c_state = RC_INPROG; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/