From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 26 Jul 2007 12:27:30 +0200 From: Ingo Molnar Subject: Re: RFT: updatedb "morning after" problem [was: Re: -mm merge plans for 2.6.23] Message-ID: <20070726102730.GA31894@elte.hu> References: <2c0942db0707232153j3670ef31kae3907dff1a24cb7@mail.gmail.com> <46A58B49.3050508@yahoo.com.au> <2c0942db0707240915h56e007e3l9110e24a065f2e73@mail.gmail.com> <46A6CC56.6040307@yahoo.com.au> <46A85D95.509@kingswood-consulting.co.uk> <20070726092025.GA9157@elte.hu> <20070726023401.f6a2fbdf.akpm@linux-foundation.org> <20070726094024.GA15583@elte.hu> <20070726030902.02f5eab0.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070726030902.02f5eab0.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Frank Kingswood , Andi Kleen , Nick Piggin , Ray Lee , Jesper Juhl , ck list , Paul Jackson , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: * Andrew Morton wrote: > > > > ( we _do_ want to baloon the dentry cache otherwise - for things like > > > > "find" - having a fast VFS is important. But known-use-once things > > > > like the daily updatedb job can clearly be annotated properly. ) > > > > > > Mutter. /proc/sys/vm/vfs_cache_pressure has been there for what, > > > three years? Are any distros raising it during the updatedb run yet? > > > > but ... that's system-wide, and the 'dont baloon the dcache' is only a > > property of updatedb. > > Sure, but it's practical, isn't it? Who runs (and cares about) > vfs-intensive workloads during their wee-small-hours updatedb run? there's another side-effect: it likely results in the zapping of thousands of dentries that were cached nicely before. So we might exchange 'all my apps are swapped out' experience with 'all file access is slow'. The latter is _probably_ still an improvement over the balooning, but i'm not sure. What we _really_ want is an updatedb that does not disturb the dcache. Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org