From: Kyle Rose Subject: Re: READDIRPLUS max mount option Date: Fri, 07 Mar 2008 16:04:05 -0500 Message-ID: <47D1ADC5.1050108@krose.org> References: <47D1995E.6060501@krose.org> <1204919978.16746.12.camel@heimdal.trondhjem.org> <47D1A0F5.2070501@krose.org> <1204922570.16746.37.camel@heimdal.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: Linux Kernel Mailing List , linux-nfs@vger.kernel.org To: Trond Myklebust Return-path: Received: from kai.krose.org ([140.186.190.96]:55286 "EHLO mail.krose.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760149AbYCGVEJ (ORCPT ); Fri, 7 Mar 2008 16:04:09 -0500 In-Reply-To: <1204922570.16746.37.camel-rJ7iovZKK19ZJLDQqaL3InhyD016LWXt@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: > The size of the actual READDIRPLUS requests is completely unaffected by > your patch. Your change actually means that the client will continue to > use READDIRPLUS on very large directories instead of falling back to > readdir. > Sorry to be imprecise. "Size of request" should be "size of response" or "cost of request". The meaning is clear, I think. > If you want a faster readdir(), you will find that splitting those huge > directories up into smaller subdirs is an alternative solution that > tends to scale much better on both client and server. > Agreed that this is probably the least terrible of the available solutions, but in my specific case it requires a more extensive modification to my software than the relatively minor kernel change. > Having hundreds of mount options for minor tweaks is not an acceptable > practice. Each mount option needs to be abundantly justified. > Regarding your straw man, nobody's proposing hundreds of mount options. I imagine the effort required to implement each one would keep such a thing from happening. ;-) > Since we're talking about what is really a quite arbitrary limit, I can > certainly see an argument for why we might want a way to change it, but > I'm still not convinced that we need to be setting this parameter at the > mountpoint level. Fair enough. A proc entry to alter this globally would be an acceptable compromise for me, even if my local sysadmins might not like it. Kyle