Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752104AbdHBVRY (ORCPT ); Wed, 2 Aug 2017 17:17:24 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:39304 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752059AbdHBVRV (ORCPT ); Wed, 2 Aug 2017 17:17:21 -0400 Date: Wed, 2 Aug 2017 14:17:20 -0700 From: Andrew Morton To: Jonathan Toppins Cc: linux-mm@kvack.org, linux-rdma@vger.kernel.org, dledford@redhat.com, Michal Hocko , Vlastimil Babka , Mel Gorman , Hillf Danton , linux-kernel@vger.kernel.org (open list) Subject: Re: [PATCH] mm: ratelimit PFNs busy info message Message-Id: <20170802141720.228502368b534f517e3107ff@linux-foundation.org> In-Reply-To: <499c0f6cc10d6eb829a67f2a4d75b4228a9b356e.1501695897.git.jtoppins@redhat.com> References: <499c0f6cc10d6eb829a67f2a4d75b4228a9b356e.1501695897.git.jtoppins@redhat.com> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 853 Lines: 21 On Wed, 2 Aug 2017 13:44:57 -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. Well... why are all these EBUSY's occurring? It sounds inefficient (at least) but if it is expected, normal and unavoidable then perhaps we should just remove that message altogether? > --- 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;