From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756290AbbCRRbc (ORCPT ); Wed, 18 Mar 2015 13:31:32 -0400 Received: from mail-ig0-f180.google.com ([209.85.213.180]:33071 "EHLO mail-ig0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753576AbbCRRb3 (ORCPT ); Wed, 18 Mar 2015 13:31:29 -0400 MIME-Version: 1.0 In-Reply-To: References: <20150309191943.GF26657@destitution> <20150312131045.GE3406@suse.de> <20150312184925.GH3406@suse.de> <20150317070655.GB10105@dastard> <20150317205104.GA28621@dastard> <20150317220840.GC28621@dastard> Date: Wed, 18 Mar 2015 10:31:28 -0700 X-Google-Sender-Auth: dBRMYon28mut5KbMLpLajG773yM Message-ID: Subject: Re: [PATCH 4/4] mm: numa: Slow PTE scan rate if migration failures occur From: Linus Torvalds To: Dave Chinner Cc: Mel Gorman , Ingo Molnar , Andrew Morton , Aneesh Kumar , Linux Kernel Mailing List , Linux-MM , xfs@oss.sgi.com, ppc-dev Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 18, 2015 at 9:08 AM, Linus Torvalds wrote: > > So why am I wrong? Why is testing for dirty not the same as testing > for writable? > > I can see a few cases: > > - your load has lots of writable (but not written-to) shared memory Hmm. I tried to look at the xfsprog sources, and I don't see any MAP_SHARED activity. It looks like it's just using pread64/pwrite64, and the only MAP_SHARED is for the xfsio mmap test thing, not for xfsrepair. So I don't see any shared mappings, but I don't know the code-base. > - something completely different that I am entirely missing So I think there's something I'm missing. For non-shared mappings, I still have the idea that pte_dirty should be the same as pte_write. And yet, your testing of 3.19 shows that it's a big difference. There's clearly something I'm completely missing. Linus From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 28EAC7F37 for ; Wed, 18 Mar 2015 12:31:34 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay1.corp.sgi.com (Postfix) with ESMTP id 074BF8F8049 for ; Wed, 18 Mar 2015 10:31:30 -0700 (PDT) Received: from mail-ie0-f169.google.com (mail-ie0-f169.google.com [209.85.223.169]) by cuda.sgi.com with ESMTP id 9wO9353dVGAZyx7G (version=TLSv1 cipher=RC4-SHA bits=128 verify=NO) for ; Wed, 18 Mar 2015 10:31:29 -0700 (PDT) Received: by iegc3 with SMTP id c3so45001074ieg.3 for ; Wed, 18 Mar 2015 10:31:28 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <20150309191943.GF26657@destitution> <20150312131045.GE3406@suse.de> <20150312184925.GH3406@suse.de> <20150317070655.GB10105@dastard> <20150317205104.GA28621@dastard> <20150317220840.GC28621@dastard> Date: Wed, 18 Mar 2015 10:31:28 -0700 Message-ID: Subject: Re: [PATCH 4/4] mm: numa: Slow PTE scan rate if migration failures occur From: Linus Torvalds List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: Linux Kernel Mailing List , xfs@oss.sgi.com, Linux-MM , Aneesh Kumar , Andrew Morton , ppc-dev , Ingo Molnar , Mel Gorman On Wed, Mar 18, 2015 at 9:08 AM, Linus Torvalds wrote: > > So why am I wrong? Why is testing for dirty not the same as testing > for writable? > > I can see a few cases: > > - your load has lots of writable (but not written-to) shared memory Hmm. I tried to look at the xfsprog sources, and I don't see any MAP_SHARED activity. It looks like it's just using pread64/pwrite64, and the only MAP_SHARED is for the xfsio mmap test thing, not for xfsrepair. So I don't see any shared mappings, but I don't know the code-base. > - something completely different that I am entirely missing So I think there's something I'm missing. For non-shared mappings, I still have the idea that pte_dirty should be the same as pte_write. And yet, your testing of 3.19 shows that it's a big difference. There's clearly something I'm completely missing. Linus _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f180.google.com (mail-ig0-f180.google.com [209.85.213.180]) by kanga.kvack.org (Postfix) with ESMTP id 32BCE6B0038 for ; Wed, 18 Mar 2015 13:31:30 -0400 (EDT) Received: by igbue6 with SMTP id ue6so77520227igb.1 for ; Wed, 18 Mar 2015 10:31:30 -0700 (PDT) Received: from mail-ig0-x234.google.com (mail-ig0-x234.google.com. [2607:f8b0:4001:c05::234]) by mx.google.com with ESMTPS id 129si18695423ion.55.2015.03.18.10.31.28 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 18 Mar 2015 10:31:29 -0700 (PDT) Received: by igbue6 with SMTP id ue6so51118253igb.1 for ; Wed, 18 Mar 2015 10:31:28 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <20150309191943.GF26657@destitution> <20150312131045.GE3406@suse.de> <20150312184925.GH3406@suse.de> <20150317070655.GB10105@dastard> <20150317205104.GA28621@dastard> <20150317220840.GC28621@dastard> Date: Wed, 18 Mar 2015 10:31:28 -0700 Message-ID: Subject: Re: [PATCH 4/4] mm: numa: Slow PTE scan rate if migration failures occur From: Linus Torvalds Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Dave Chinner Cc: Mel Gorman , Ingo Molnar , Andrew Morton , Aneesh Kumar , Linux Kernel Mailing List , Linux-MM , xfs@oss.sgi.com, ppc-dev On Wed, Mar 18, 2015 at 9:08 AM, Linus Torvalds wrote: > > So why am I wrong? Why is testing for dirty not the same as testing > for writable? > > I can see a few cases: > > - your load has lots of writable (but not written-to) shared memory Hmm. I tried to look at the xfsprog sources, and I don't see any MAP_SHARED activity. It looks like it's just using pread64/pwrite64, and the only MAP_SHARED is for the xfsio mmap test thing, not for xfsrepair. So I don't see any shared mappings, but I don't know the code-base. > - something completely different that I am entirely missing So I think there's something I'm missing. For non-shared mappings, I still have the idea that pte_dirty should be the same as pte_write. And yet, your testing of 3.19 shows that it's a big difference. There's clearly something I'm completely missing. Linus -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-x22c.google.com (mail-ie0-x22c.google.com [IPv6:2607:f8b0:4001:c03::22c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 016F41A02F4 for ; Thu, 19 Mar 2015 04:31:30 +1100 (AEDT) Received: by ieclw3 with SMTP id lw3so44666490iec.2 for ; Wed, 18 Mar 2015 10:31:28 -0700 (PDT) MIME-Version: 1.0 Sender: linus971@gmail.com In-Reply-To: References: <20150309191943.GF26657@destitution> <20150312131045.GE3406@suse.de> <20150312184925.GH3406@suse.de> <20150317070655.GB10105@dastard> <20150317205104.GA28621@dastard> <20150317220840.GC28621@dastard> Date: Wed, 18 Mar 2015 10:31:28 -0700 Message-ID: Subject: Re: [PATCH 4/4] mm: numa: Slow PTE scan rate if migration failures occur From: Linus Torvalds To: Dave Chinner Content-Type: text/plain; charset=UTF-8 Cc: Linux Kernel Mailing List , xfs@oss.sgi.com, Linux-MM , Aneesh Kumar , Andrew Morton , ppc-dev , Ingo Molnar , Mel Gorman List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Mar 18, 2015 at 9:08 AM, Linus Torvalds wrote: > > So why am I wrong? Why is testing for dirty not the same as testing > for writable? > > I can see a few cases: > > - your load has lots of writable (but not written-to) shared memory Hmm. I tried to look at the xfsprog sources, and I don't see any MAP_SHARED activity. It looks like it's just using pread64/pwrite64, and the only MAP_SHARED is for the xfsio mmap test thing, not for xfsrepair. So I don't see any shared mappings, but I don't know the code-base. > - something completely different that I am entirely missing So I think there's something I'm missing. For non-shared mappings, I still have the idea that pte_dirty should be the same as pte_write. And yet, your testing of 3.19 shows that it's a big difference. There's clearly something I'm completely missing. Linus