From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: [PATCH 8/9] sunrpc/cache: change deferred-request hash table to use hlist. Date: Wed, 09 Sep 2009 16:32:55 +1000 Message-ID: <20090909063254.20462.93058.stgit@notabene.brown> References: <20090909062539.20462.67466.stgit@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linux-nfs@vger.kernel.org, NeilBrown To: "J. Bruce Fields" Return-path: Received: from cantor.suse.de ([195.135.220.2]:37979 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751787AbZIIGd0 (ORCPT ); Wed, 9 Sep 2009 02:33:26 -0400 In-Reply-To: <20090909062539.20462.67466.stgit-wvvUuzkyo1EYVZTmpyfIwg@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: Being a hash table, hlist is the best option. There is currently some ugliness were we treat "->next == NULL" as a special case to avoid having to initialise the whole array. This change nicely gets rid of that case. Signed-off-by: NeilBrown --- include/linux/sunrpc/cache.h | 2 +- net/sunrpc/cache.c | 30 ++++++++++++------------------ 2 files changed, 13 insertions(+), 19 deletions(-) diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h index ef3db11..ba9d72c 100644 --- a/include/linux/sunrpc/cache.h +++ b/include/linux/sunrpc/cache.h @@ -133,7 +133,7 @@ struct cache_req { * delayed awaiting cache-fill */ struct cache_deferred_req { - struct list_head hash; /* on hash chain */ + struct hlist_node hash; /* on hash chain */ struct list_head recent; /* on fifo */ struct cache_head *item; /* cache item we wait on */ void *owner; /* we might need to discard all defered requests diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 46e9e2b..dab417c 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -495,7 +495,7 @@ EXPORT_SYMBOL_GPL(cache_purge); static DEFINE_SPINLOCK(cache_defer_lock); static LIST_HEAD(cache_defer_list); -static struct list_head cache_defer_hash[DFR_HASHSIZE]; +static struct hlist_head cache_defer_hash[DFR_HASHSIZE]; static int cache_defer_cnt; struct thread_deferred_req { @@ -539,9 +539,7 @@ static int cache_defer_req(struct cache_req *req, struct cache_head *item) list_add(&dreq->recent, &cache_defer_list); - if (cache_defer_hash[hash].next == NULL) - INIT_LIST_HEAD(&cache_defer_hash[hash]); - list_add(&dreq->hash, &cache_defer_hash[hash]); + hlist_add_head(&dreq->hash, &cache_defer_hash[hash]); /* it is in, now maybe clean up */ discard = NULL; @@ -549,7 +547,7 @@ static int cache_defer_req(struct cache_req *req, struct cache_head *item) discard = list_entry(cache_defer_list.prev, struct cache_deferred_req, recent); list_del_init(&discard->recent); - list_del_init(&discard->hash); + hlist_del_init(&discard->hash); cache_defer_cnt--; } spin_unlock(&cache_defer_lock); @@ -568,12 +566,12 @@ static int cache_defer_req(struct cache_req *req, struct cache_head *item) wait_event_interruptible_timeout( sleeper.wait, !test_bit(CACHE_PENDING, &item->flags) - || list_empty(&sleeper.handle.hash), + || hlist_unhashed(&sleeper.handle.hash), req->thread_wait); spin_lock(&cache_defer_lock); - if (!list_empty(&sleeper.handle.hash)) { + if (!hlist_unhashed(&sleeper.handle.hash)) { list_del_init(&sleeper.handle.recent); - list_del_init(&sleeper.handle.hash); + hlist_del_init(&sleeper.handle.hash); cache_defer_cnt--; } spin_unlock(&cache_defer_lock); @@ -594,24 +592,20 @@ static void cache_revisit_request(struct cache_head *item) struct cache_deferred_req *dreq; struct list_head pending; - struct list_head *lp; + struct hlist_node *lp, *tmp; int hash = DFR_HASH(item); INIT_LIST_HEAD(&pending); spin_lock(&cache_defer_lock); - lp = cache_defer_hash[hash].next; - if (lp) { - while (lp != &cache_defer_hash[hash]) { - dreq = list_entry(lp, struct cache_deferred_req, hash); - lp = lp->next; + hlist_for_each_entry_safe(dreq, lp, tmp, + &cache_defer_hash[hash], hash) if (dreq->item == item) { - list_del_init(&dreq->hash); + hlist_del_init(&dreq->hash); list_move(&dreq->recent, &pending); cache_defer_cnt--; } - } - } + spin_unlock(&cache_defer_lock); while (!list_empty(&pending)) { @@ -632,7 +626,7 @@ void cache_clean_deferred(void *owner) list_for_each_entry_safe(dreq, tmp, &cache_defer_list, recent) { if (dreq->owner == owner) { - list_del_init(&dreq->hash); + hlist_del_init(&dreq->hash); list_move(&dreq->recent, &pending); cache_defer_cnt--; }