Return-Path: Received: from fieldses.org ([173.255.197.46]:60866 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755724AbbKEVbh (ORCPT ); Thu, 5 Nov 2015 16:31:37 -0500 Date: Thu, 5 Nov 2015 16:31:34 -0500 From: "J. Bruce Fields" To: Jeff Layton Cc: linux-nfs@vger.kernel.org Subject: Re: [PATCH] nfsd: remove recurring workqueue job to clean DRC Message-ID: <20151105213134.GI9210@fieldses.org> References: <1446652949-16672-1-git-send-email-jeff.layton@primarydata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1446652949-16672-1-git-send-email-jeff.layton@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Nov 04, 2015 at 11:02:29AM -0500, Jeff Layton wrote: > We have a shrinker, we clean out the cache when nfsd is shut down, and > prune the chains on each request. A recurring workqueue job seems like > unnecessary overhead. Just remove it. Thanks, applying.--b. > > Signed-off-by: Jeff Layton > --- > fs/nfsd/nfscache.c | 26 -------------------------- > 1 file changed, 26 deletions(-) > > diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c > index 46ec934f5dee..8af64b6ffe91 100644 > --- a/fs/nfsd/nfscache.c > +++ b/fs/nfsd/nfscache.c > @@ -63,7 +63,6 @@ static unsigned int longest_chain; > static unsigned int longest_chain_cachesize; > > static int nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec); > -static void cache_cleaner_func(struct work_struct *unused); > static unsigned long nfsd_reply_cache_count(struct shrinker *shrink, > struct shrink_control *sc); > static unsigned long nfsd_reply_cache_scan(struct shrinker *shrink, > @@ -76,13 +75,6 @@ static struct shrinker nfsd_reply_cache_shrinker = { > }; > > /* > - * locking for the reply cache: > - * A cache entry is "single use" if c_state == RC_INPROG > - * Otherwise, it when accessing _prev or _next, the lock must be held. > - */ > -static DECLARE_DELAYED_WORK(cache_cleaner, cache_cleaner_func); > - > -/* > * Put a cap on the size of the DRC based on the amount of available > * low memory in the machine. > * > @@ -203,7 +195,6 @@ void nfsd_reply_cache_shutdown(void) > unsigned int i; > > unregister_shrinker(&nfsd_reply_cache_shrinker); > - cancel_delayed_work_sync(&cache_cleaner); > > for (i = 0; i < drc_hashsize; i++) { > struct list_head *head = &drc_hashtbl[i].lru_head; > @@ -232,7 +223,6 @@ lru_put_end(struct nfsd_drc_bucket *b, struct svc_cacherep *rp) > { > rp->c_timestamp = jiffies; > list_move_tail(&rp->c_lru, &b->lru_head); > - schedule_delayed_work(&cache_cleaner, RC_EXPIRE); > } > > static long > @@ -266,7 +256,6 @@ prune_cache_entries(void) > { > unsigned int i; > long freed = 0; > - bool cancel = true; > > for (i = 0; i < drc_hashsize; i++) { > struct nfsd_drc_bucket *b = &drc_hashtbl[i]; > @@ -275,26 +264,11 @@ prune_cache_entries(void) > continue; > spin_lock(&b->cache_lock); > freed += prune_bucket(b); > - if (!list_empty(&b->lru_head)) > - cancel = false; > spin_unlock(&b->cache_lock); > } > - > - /* > - * Conditionally rearm the job to run in RC_EXPIRE since we just > - * ran the pruner. > - */ > - if (!cancel) > - mod_delayed_work(system_wq, &cache_cleaner, RC_EXPIRE); > return freed; > } > > -static void > -cache_cleaner_func(struct work_struct *unused) > -{ > - prune_cache_entries(); > -} > - > static unsigned long > nfsd_reply_cache_count(struct shrinker *shrink, struct shrink_control *sc) > { > -- > 2.4.3