From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve French Subject: Re: [linux-cifs-client] [PATCH] cifs: implement drop_inode superblock op Date: Thu, 27 May 2010 09:51:40 -0500 Message-ID: References: <1274815488-29173-1-git-send-email-jlayton@redhat.com> <20100525200920.774cf77e@corrin.poochiereds.net> <4BFDAC6F.2090604@gmail.com> <20100527093854.49c0cb69@barsoom.rdu.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: Scott Lovenberg , linux-fsdevel@vger.kernel.org, linux-cifs-client@lists.samba.org To: Jeff Layton Return-path: Received: from mail-qy0-f183.google.com ([209.85.221.183]:54783 "EHLO mail-qy0-f183.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755921Ab0E0Ovm (ORCPT ); Thu, 27 May 2010 10:51:42 -0400 Received: by qyk13 with SMTP id 13so90070qyk.1 for ; Thu, 27 May 2010 07:51:41 -0700 (PDT) In-Reply-To: <20100527093854.49c0cb69@barsoom.rdu.redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Cached metadata will still be valid for 1 second - do these still have dentries pointing to them? On Thu, May 27, 2010 at 8:38 AM, Jeff Layton wrote: > On Wed, 26 May 2010 19:19:11 -0400 > Scott Lovenberg wrote: > >> >> >> Any rough idea of performance or memory savings (even in something >> >> artificial like dbench run)? >> >> >> >> >> > It's more of a memory savings thing. When I mount with -o noserverino >> > and run fsstress on the mount, I'd regularly see the size of the >> > cifs_inode_cache hit 60M or more (on a client with 1G RAM). With this >> > patch in place, it rarely goes over 2M in size. >> > >> > Eventually, memory pressure will force the size to go down, but if we >> > know that they'll never be used again (which is the case with >> > noserverino), it's better to go ahead and just free them. >> > >> > >> I take it this overrides the behavior of the vfs_cache_pressure before >> the memory pressure makes reclaiming cache necessary? > > Not exactly. vfs_cache_pressure just governs the way in which the VM > subsystem will attempt to free memory when it needs it by changing the > preference for flushing inode and dentry caches. > > This patch just aims to delete inodes that we know will never be used > again as soon as their refcount drops to 0. > > -- > Jeff Layton > -- Thanks, Steve