From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755304AbdBQCHU (ORCPT ); Thu, 16 Feb 2017 21:07:20 -0500 Received: from mga05.intel.com ([192.55.52.43]:54178 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754071AbdBQCHS (ORCPT ); Thu, 16 Feb 2017 21:07:18 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,170,1484035200"; d="scan'208";a="1109817282" From: "Huang\, Ying" To: Hugh Dickins Cc: Tim Chen , "Huang\, Ying" , Minchan Kim , Andrew Morton , , Subject: Re: swap_cluster_info lockdep splat References: <20170216052218.GA13908@bbox> <87o9y2a5ji.fsf@yhuang-dev.intel.com> <1487273646.2833.100.camel@linux.intel.com> Date: Fri, 17 Feb 2017 10:07:15 +0800 In-Reply-To: (Hugh Dickins's message of "Thu, 16 Feb 2017 17:46:44 -0800") Message-ID: <87efyx8t9o.fsf@yhuang-dev.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Hugh, Hugh Dickins writes: > On Thu, 16 Feb 2017, Tim Chen wrote: >> >> > I do not understand your zest for putting wrappers around every little >> > thing, making it all harder to follow than it need be.  Here's the patch >> > I've been running with (but you have a leak somewhere, and I don't have >> > time to search out and fix it: please try sustained swapping and swapoff). >> > >> >> Hugh, trying to duplicate your test case.  So you were doing swapping, >> then swap off, swap on the swap device and restart swapping? > > Repeated pair of make -j20 kernel builds in 700M RAM, 1.5G swap on SSD, > 8 cpus; one of the builds in tmpfs, other in ext4 on loop on tmpfs file; > sizes tuned for plenty of swapping but no OOMing (it's an ancient 2.6.24 > kernel I build, modern one needing a lot more space with a lot less in use). > > How much of that is relevant I don't know: hopefully none of it, it's > hard to get the tunings right from scratch. To answer your specific > question: yes, I'm not doing concurrent swapoffs in this test showing > the leak, just waiting for each of the pair of builds to complete, > then tearing down the trees, doing swapoff followed by swapon, and > starting a new pair of builds. > > Sometimes it's the swapoff that fails with ENOMEM, more often it's a > fork during build that fails with ENOMEM: after 6 or 7 hours of load > (but timings show it getting slower leading up to that). /proc/meminfo > did not give me an immediate clue, Slab didn't look surprising but > I may not have studied close enough. Thanks for you information! Memory newly allocated in the mm-swap series are allocated via vmalloc, could you find anything special for vmalloc in /proc/meminfo? Best Regards, Huang, Ying > I quilt-bisected it as far as the mm-swap series, good before, bad > after, but didn't manage to narrow it down further because of hitting > a presumably different issue inside the series, where swapoff ENOMEMed > much sooner (after 25 mins one time, during first iteration the next). > > Hugh From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 3C509681021 for ; Thu, 16 Feb 2017 21:07:30 -0500 (EST) Received: by mail-pf0-f198.google.com with SMTP id 145so46896009pfv.6 for ; Thu, 16 Feb 2017 18:07:30 -0800 (PST) Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTPS id o3si8734766pfk.8.2017.02.16.18.07.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 16 Feb 2017 18:07:29 -0800 (PST) From: "Huang\, Ying" Subject: Re: swap_cluster_info lockdep splat References: <20170216052218.GA13908@bbox> <87o9y2a5ji.fsf@yhuang-dev.intel.com> <1487273646.2833.100.camel@linux.intel.com> Date: Fri, 17 Feb 2017 10:07:15 +0800 In-Reply-To: (Hugh Dickins's message of "Thu, 16 Feb 2017 17:46:44 -0800") Message-ID: <87efyx8t9o.fsf@yhuang-dev.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: Tim Chen , "Huang, Ying" , Minchan Kim , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org Hi, Hugh, Hugh Dickins writes: > On Thu, 16 Feb 2017, Tim Chen wrote: >> >> > I do not understand your zest for putting wrappers around every little >> > thing, making it all harder to follow than it need be.A Here's the patch >> > I've been running with (but you have a leak somewhere, and I don't have >> > time to search out and fix it: please try sustained swapping and swapoff). >> > >> >> Hugh, trying to duplicate your test case. A So you were doing swapping, >> then swap off, swap on the swap device and restart swapping? > > Repeated pair of make -j20 kernel builds in 700M RAM, 1.5G swap on SSD, > 8 cpus; one of the builds in tmpfs, other in ext4 on loop on tmpfs file; > sizes tuned for plenty of swapping but no OOMing (it's an ancient 2.6.24 > kernel I build, modern one needing a lot more space with a lot less in use). > > How much of that is relevant I don't know: hopefully none of it, it's > hard to get the tunings right from scratch. To answer your specific > question: yes, I'm not doing concurrent swapoffs in this test showing > the leak, just waiting for each of the pair of builds to complete, > then tearing down the trees, doing swapoff followed by swapon, and > starting a new pair of builds. > > Sometimes it's the swapoff that fails with ENOMEM, more often it's a > fork during build that fails with ENOMEM: after 6 or 7 hours of load > (but timings show it getting slower leading up to that). /proc/meminfo > did not give me an immediate clue, Slab didn't look surprising but > I may not have studied close enough. Thanks for you information! Memory newly allocated in the mm-swap series are allocated via vmalloc, could you find anything special for vmalloc in /proc/meminfo? Best Regards, Huang, Ying > I quilt-bisected it as far as the mm-swap series, good before, bad > after, but didn't manage to narrow it down further because of hitting > a presumably different issue inside the series, where swapoff ENOMEMed > much sooner (after 25 mins one time, during first iteration the next). > > Hugh -- 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