Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752501AbdHBSFX (ORCPT ); Wed, 2 Aug 2017 14:05:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43252 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751600AbdHBSFW (ORCPT ); Wed, 2 Aug 2017 14:05:22 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com BB8A7883A2 Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=dledford@redhat.com Message-ID: <1501697116.109555.9.camel@redhat.com> Subject: Re: [PATCH] mm: ratelimit PFNs busy info message From: Doug Ledford To: Jonathan Toppins , linux-mm@kvack.org Cc: linux-rdma@vger.kernel.org, Andrew Morton , Michal Hocko , Vlastimil Babka , Mel Gorman , Hillf Danton , open list In-Reply-To: <499c0f6cc10d6eb829a67f2a4d75b4228a9b356e.1501695897.git.jtoppins@redhat.com> References: <499c0f6cc10d6eb829a67f2a4d75b4228a9b356e.1501695897.git.jtoppins@redhat.com> Organization: Red Hat, Inc. Content-Type: text/plain; charset="UTF-8" Date: Wed, 02 Aug 2017 14:05:16 -0400 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 02 Aug 2017 18:05:22 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1565 Lines: 41 On Wed, 2017-08-02 at 13:44 -0400, Jonathan Toppins wrote: > The RDMA subsystem can generate several thousand of these messages > per > second eventually leading to a kernel crash. Ratelimit these messages > to prevent this crash. > > Signed-off-by: Jonathan Toppins > Reviewed-by: Doug Ledford > Tested-by: Doug Ledford > --- > mm/page_alloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 6d30e914afb6..07b7d3060b21 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -7666,7 +7666,7 @@ int alloc_contig_range(unsigned long start, > unsigned long end, > > /* Make sure the range is really isolated. */ > if (test_pages_isolated(outer_start, end, false)) { > - pr_info("%s: [%lx, %lx) PFNs busy\n", > + pr_info_ratelimited("%s: [%lx, %lx) PFNs busy\n", > __func__, outer_start, end); > ret = -EBUSY; > goto done; FWIW, I've been carrying a version of this for several kernel versions. I don't remember when they started, but we have one (and only one) class of machines: Dell PE R730xd, that generate these errors. When it happens, without a rate limit, we get rcu timeouts and kernel oopses. With the rate limit, we just get a lot of annoying kernel messages but the machine continues on, recovers, and eventually the memory operations all succeed. -- Doug Ledford GPG KeyID: B826A3330E572FDD Key fingerprint = AE6B 1BDA 122B 23B4 265B 1274 B826 A333 0E57 2FDD