From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx122.postini.com [74.125.245.122]) by kanga.kvack.org (Postfix) with SMTP id E2DD76B005D for ; Mon, 10 Dec 2012 07:35:07 -0500 (EST) Received: by mail-bk0-f41.google.com with SMTP id jg9so1285331bkc.14 for ; Mon, 10 Dec 2012 04:35:06 -0800 (PST) Date: Mon, 10 Dec 2012 13:35:01 +0100 From: Ingo Molnar Subject: Re: [PATCH 00/49] Automatic NUMA Balancing v10 Message-ID: <20121210123501.GA8968@gmail.com> References: <1354875832-9700-1-git-send-email-mgorman@suse.de> <20121207110113.GB21482@gmail.com> <20121209203630.GC1009@suse.de> <20121210050710.GC22164@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121210050710.GC22164@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Srikar Dronamraju Cc: Mel Gorman , Peter Zijlstra , Andrea Arcangeli , Rik van Riel , Johannes Weiner , Hugh Dickins , Thomas Gleixner , Paul Turner , Hillf Danton , David Rientjes , Lee Schermerhorn , Alex Shi , Aneesh Kumar , Linus Torvalds , Andrew Morton , Linux-MM , LKML hi Srikar, * Srikar Dronamraju wrote: > > > > Either way, last night I applied a patch on top of latest tip/master to > > remove the nr_cpus_allowed check so that numacore would be enabled again > > and tested that. In some places it has indeed much improved. In others > > it is still regressing badly and in two case, it's corrupting memory -- > > specjbb when THP is enabled crashes when running for single or multiple > > JVMs. It is likely that a zero page is being inserted due to a race with > > migration and causes the JVM to throw a null pointer exception. Here is > > the comparison on the rough off-chance you actually read it this time. > > I see this failure when running with THP and KSM enabled on > Friday's Tip master. Not sure if Mel was talking about the same issue. > > ------------[ cut here ]------------ > kernel BUG at ../kernel/sched/fair.c:2371! Could you check whether today's -tip (7ea8701a1a51 or later), plus the patch below, addresses the crash - while still giving good NUMA performance? Thanks, Ingo diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 9d11a8a..6a89787 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2351,6 +2351,9 @@ void task_numa_fault(unsigned long addr, int node, int last_cpupid, int pages, b int priv; int idx; + if (!p->numa_faults) + return; + if (last_cpupid != cpu_pid_to_cpupid(-1, -1)) { /* Did we access it last time around? */ if (last_pid == this_pid) { -- 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