From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 7 Mar 2007 10:38:48 +0100 From: Nick Piggin Subject: Re: [patch 4/6] mm: merge populate and nopage into fault (fixes nonlinear) Message-ID: <20070307093848.GC8609@wotan.suse.de> References: <20070306225101.f393632c.akpm@linux-foundation.org> <20070307070853.GB15877@wotan.suse.de> <20070307081948.GA9563@wotan.suse.de> <20070307082755.GA25733@elte.hu> <20070307004709.432ddf97.akpm@linux-foundation.org> <20070307010756.b31c8190.akpm@linux-foundation.org> <20070307091823.GA8609@wotan.suse.de> <20070307012638.793d9a9f.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070307012638.793d9a9f.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: Miklos Szeredi , mingo@elte.hu, linux-mm@kvack.org, linux-kernel@vger.kernel.org, benh@kernel.crashing.org, Peter Zijlstra List-ID: On Wed, Mar 07, 2007 at 01:26:38AM -0800, Andrew Morton wrote: > On Wed, 7 Mar 2007 10:18:23 +0100 Nick Piggin wrote: > > > > > msync breakage is bad, but otherwise I don't know that we care about > > dirty page writeout efficiency. > > Well. We made so many changes to support the synchronous > dirty-the-page-when-we-dirty-the-pte thing that I'm rather doubtful that > the old-style approach still works. It might seem to, most of the time. > But if it _is_ subtly broken, boy it's going to take a long time for us to > find out. I can't think of anything that should have caused breakage (except for the msync thing). We're still careful about not dropping pte dirty bits. > > But I think we discovered that those msync changes are bogus anyway > > becuase there is a small race window where pte could be dirtied without > > page being set dirty? > > Dunno, I don't recall that. We dirty the page before the pte... I don't think it isn't really that simple. There is a big comment in clear_page_dirty_for_io. -- 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