From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <45BD5E8D.6080206@yahoo.com.au> Date: Mon, 29 Jan 2007 13:40:13 +1100 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [RFC 0/8] Use ZVCs for accurate writeback ratio determination References: <20070126054153.10564.43218.sendpatchset@schroedinger.engr.sgi.com> <45B9F26D.5090107@yahoo.com.au> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: akpm@osdl.org, Peter Zijlstra , linux-mm@kvack.org, Nikita Danilov , Andi Kleen List-ID: Christoph Lameter wrote: > On Fri, 26 Jan 2007, Nick Piggin wrote: > > >>So you no longer account for reclaimable slab allocations, which >>would be a significant change on some workloads. Any reason for >>that? > > > We could add NR_SLAB_RECLAIMABLE if that is a factor. However, > these pages cannot be dirtied. They may be reclaimed yes and then pages > may become available again. However, that is a difficult process without > slab defrag. Are you sure that these are significant? I think so. I have seen systems that get very full of dcache/icache, and little to no pagecache. In that case it makes no sense to limit dirty pages to a potentially small amount. Slab reclaim does work. It may not be perfect, but I don't think that should spill over into dirty page calculations. If anything we need to improve slab reclaimability estimates for that. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com -- 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