From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 29 Jan 2007 08:56:05 -0800 (PST) From: Christoph Lameter Subject: Re: [RFC 0/8] Use ZVCs for accurate writeback ratio determination In-Reply-To: <45BD5E8D.6080206@yahoo.com.au> Message-ID: References: <20070126054153.10564.43218.sendpatchset@schroedinger.engr.sgi.com> <45B9F26D.5090107@yahoo.com.au> <45BD5E8D.6080206@yahoo.com.au> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: akpm@osdl.org, Peter Zijlstra , linux-mm@kvack.org, Nikita Danilov , Andi Kleen List-ID: On Mon, 29 Jan 2007, Nick Piggin wrote: > > 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. How about adding NR_SLAB_RECLAIMABLE / 2 to take the reclaim problems into account that may lead to many pages not be recoverable? -- 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