From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: Re: [PATCH 12/13] dcache: remove dentries from LRU before putting on dispose list Date: Tue, 23 Aug 2011 19:57:52 +1000 Message-ID: <20110823095752.GB3162@dastard> References: <1314089786-20535-1-git-send-email-david@fromorbit.com> <1314089786-20535-13-git-send-email-david@fromorbit.com> <20110823093520.GA4938@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, khlebnikov@openvz.org To: Christoph Hellwig Return-path: Received: from ipmail07.adl2.internode.on.net ([150.101.137.131]:63250 "EHLO ipmail07.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750982Ab1HWJ5z (ORCPT ); Tue, 23 Aug 2011 05:57:55 -0400 Content-Disposition: inline In-Reply-To: <20110823093520.GA4938@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, Aug 23, 2011 at 05:35:20AM -0400, Christoph Hellwig wrote: > > diff --git a/fs/dcache.c b/fs/dcache.c > > index b931415..79bf47c 100644 > > --- a/fs/dcache.c > > +++ b/fs/dcache.c > > @@ -269,10 +269,10 @@ static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list) > > spin_lock(&dentry->d_sb->s_dentry_lru_lock); > > if (list_empty(&dentry->d_lru)) { > > list_add_tail(&dentry->d_lru, list); > > - dentry->d_sb->s_nr_dentry_unused++; > > - this_cpu_inc(nr_dentry_unused); > > } else { > > list_move_tail(&dentry->d_lru, list); > > + dentry->d_sb->s_nr_dentry_unused--; > > + this_cpu_dec(nr_dentry_unused); > > } > > spin_unlock(&dentry->d_sb->s_dentry_lru_lock); > > I suspect at this point it might be more obvious to simply remove > dentry_lru_move_list. Just call dentry_lru_del to remove it from the > lru, and then we can add it to the local dispose list without the need > of any locking, similar to how it is done for inodes already. Yeah, that is what is done in the next patch when converting to the generic LRU list code. I can probably pull this back into this patch and just remove dentry_lru_move_list(0 right here. > > > if (dentry->d_count) { > > - dentry_lru_del(dentry); > > spin_unlock(&dentry->d_lock); > > continue; > > } > > @@ -789,6 +794,8 @@ relock: > > spin_unlock(&dentry->d_lock); > > } else { > > list_move_tail(&dentry->d_lru, &tmp); > > + this_cpu_dec(nr_dentry_unused); > > + sb->s_nr_dentry_unused--; > > It might be more obvious to use __dentry_lru_del + an opencoded list_add > here. This goes away completely in the next patch, so I don't think it matters that much... Cheers, Dave. -- Dave Chinner david@fromorbit.com