From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262790AbUBZNxg (ORCPT ); Thu, 26 Feb 2004 08:53:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262794AbUBZNxg (ORCPT ); Thu, 26 Feb 2004 08:53:36 -0500 Received: from unthought.net ([212.97.129.88]:32979 "EHLO unthought.net") by vger.kernel.org with ESMTP id S262790AbUBZNxe (ORCPT ); Thu, 26 Feb 2004 08:53:34 -0500 Date: Thu, 26 Feb 2004 14:53:33 +0100 From: Jakob Oestergaard To: Marcelo Tosatti Cc: linux-kernel@vger.kernel.org Subject: Re: 2.4.25 - large inode_cache Message-ID: <20040226135333.GQ29776@unthought.net> Mail-Followup-To: Jakob Oestergaard , Marcelo Tosatti , linux-kernel@vger.kernel.org References: <20040226013313.GN29776@unthought.net> <20040226111912.GB4554@core.home> <20040226130344.GP29776@unthought.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 26, 2004 at 11:23:46AM -0300, Marcelo Tosatti wrote: ... > > Will a heap of busy knfsd processes doing reads or writes exert > > pressure? Or is it only local userspace that can pressurize the VM (by > > either anonymously backed memory or file I/O). > > Any allocator will cause VM pressure. And I suppose that a busy knfsd qualifies as an "allocator" :) ... > > Any enlightenment or suggestions are greatly appreciated :) > > What you can try is to increase the VM tunable vm_vfs_scan_ratio. This is > the proportion of VFS unused d/i caches that will try to be in one VM > freeing pass. The default is 6. Try 4 or 3. > > /proc/sys/vm/vm_vfs_scan_ratio Done! Set to 3 now - I will let the box run with this setting until tomorrow, and report back how things look. > You can also play with > > /proc/sys/vm/vm_cache_scan_ratio (which is the percentage of cache which > will be scanned in one go). I'm leaving this one be for now (one variable at a time). But let's see what tomorrow brings. Judging from the code, it seems that it's the vm_vfs_scan_ratio that directly affects the icache/dcache and dquot - but I'm sure that there are subtle interactions far beyond what I can possibly hope to comprehend ;) Thanks a lot for your suggestions Marcelo! / jakob