From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 19 Jan 2007 09:20:03 -0800 (PST) From: Christoph Lameter Subject: Re: [PATCH] nfs: fix congestion control In-Reply-To: <1169212022.6197.148.camel@twins> Message-ID: References: <20070116054743.15358.77287.sendpatchset@schroedinger.engr.sgi.com> <20070116135325.3441f62b.akpm@osdl.org> <1168985323.5975.53.camel@lappy> <1169070763.5975.70.camel@lappy> <1169070886.6523.8.camel@lade.trondhjem.org> <1169126868.6197.55.camel@twins> <1169135375.6105.15.camel@lade.trondhjem.org> <1169199234.6197.129.camel@twins> <1169212022.6197.148.camel@twins> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Peter Zijlstra Cc: Trond Myklebust , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, pj@sgi.com List-ID: On Fri, 19 Jan 2007, Peter Zijlstra wrote: > + /* > + * NFS congestion size, scale with available memory. > + * Well this all depends on the memory available to the running process. If the process is just allowed to allocate from a subset of memory (cpusets) then this may need to be lower. > + * 64MB: 8192k > + * 128MB: 11585k > + * 256MB: 16384k > + * 512MB: 23170k > + * 1GB: 32768k > + * 2GB: 46340k > + * 4GB: 65536k > + * 8GB: 92681k > + * 16GB: 131072k Hmmm... lets say we have the worst case of an 8TB IA64 system with 1k nodes of 8G each. On Ia64 the number of pages is 8TB/16KB pagesize = 512 million pages. Thus nfs_congestion_size is 724064 pages which is 11.1Gbytes? If we now restrict a cpuset to a single node then have a nfs_congestion_size of 11.1G vs an available memory on a node of 8G. -- 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