From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx108.postini.com [74.125.245.108]) by kanga.kvack.org (Postfix) with SMTP id 98D6B6B005C for ; Wed, 4 Jan 2012 15:20:26 -0500 (EST) Date: Wed, 4 Jan 2012 12:20:25 -0800 From: Andrew Morton Subject: Re: [PATCH 3/3] mm: take pagevecs off reclaim stack Message-Id: <20120104122025.b0890e7e.akpm@linux-foundation.org> In-Reply-To: References: <20111229145548.e34cb2f3.akpm@linux-foundation.org> <4EFD04B2.7050407@gmail.com> <20111229195917.13f15974.akpm@linux-foundation.org> <20120103151236.893d2460.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: KOSAKI Motohiro , Konstantin Khlebnikov , linux-mm@kvack.org, Mel Gorman On Tue, 3 Jan 2012 19:22:42 -0800 (PST) Hugh Dickins wrote: > > > > > > > > Now, a way out here is to remove lumpy reclaim (please). And make the > > > > problem not come back by promising to never call putback_lru_pages(lots > > > > of pages) (how do we do this?). > > > > > > We can very easily put a counter in it, doing a spin_unlock_irq every > > > time we hit the max. Nothing prevents that, it's just an excrescence > > > I'd have preferred to omit and have not today implemented. > > > > Yes. It's ultra-cautious, but perhaps we should do this at least until > > lumpy goes away. > > I don't think you'll accept my observations above as excuse to do > nothing, but please clarify which you think is more cautious. Should > I or should I not break up the isolating end in the same way as the > putting back? If we already have the latency problem at the isolate_lru_pages() stage then I suppose we can assume that nobody is noticing it, so we'll probably be OK. For a while. Someone will complain at some stage and we'll probably end up busting this work into chunks. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org