From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 50F866B004D for ; Tue, 9 Jun 2009 10:46:32 -0400 (EDT) Date: Tue, 9 Jun 2009 22:56:14 +0800 From: Wu Fengguang Subject: Re: [PATCH] [11/16] HWPOISON: check and isolate corrupted free pages v2 Message-ID: <20090609145614.GA5590@localhost> References: <20090603846.816684333@firstfloor.org> <20090603184645.68FA21D0286@basil.firstfloor.org> <20090609100229.GE14820@wotan.suse.de> <20090609130304.GF5589@localhost> <20090609132847.GC15219@wotan.suse.de> <20090609134903.GC6583@localhost> <20090609135514.GD15219@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090609135514.GD15219@wotan.suse.de> Sender: owner-linux-mm@kvack.org To: Nick Piggin Cc: Andi Kleen , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" List-ID: On Tue, Jun 09, 2009 at 09:55:14PM +0800, Nick Piggin wrote: > On Tue, Jun 09, 2009 at 09:49:03PM +0800, Wu Fengguang wrote: > > On Tue, Jun 09, 2009 at 09:28:47PM +0800, Nick Piggin wrote: > > > And I don't think removing a free page from the page allocator is > > > too much more complex than removing a live page from the pagecache ;) > > > > There are usable functions for doing pagecache isolations, but no one > > to isolate one specific page from the buddy system. > > But it shouldn't be too hard. Anyway you wanted to reinvent your > own functions for pagecache isolations ;) Heh. > > Plus, if we did present such a function, you'll then ask for it being > > included in page_alloc.c, injecting a big chunk of dead code into the > > really hot code blocks and possibly polluting the L2 cache. Will it be > > But you would say no because you like it better in your memory > isolation file ;) I would like to align with your principle on this one :) > > better than just inserting several lines? Hardly. Smaller text itself > > yields faster speed. > > Oh speed I'm definitely thinking about, don't worry about that. > > Moving hot and cold functions together could become an issue > indeed. Mostly it probably matters a little less than code > within a single function due to their size. But I think gcc > already has options to annotate this kind of thing which we > could be using. Can we tell gcc "I bet this _function_ is rarely used"? > So it's not such a good argument against moving things out of > hotpaths, or guiding in which files to place functions. Yes. > Anyway, in this case it is not a "nack" from me. Just that I > would like to see the non-fastpath code too or at least if > it can be thought about. I think Andi would be pleased to present you with his buddy page isolation code :) Thanks, Fengguang -- 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