Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755160AbZGPKhW (ORCPT ); Thu, 16 Jul 2009 06:37:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755090AbZGPKhV (ORCPT ); Thu, 16 Jul 2009 06:37:21 -0400 Received: from gir.skynet.ie ([193.1.99.77]:53063 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755072AbZGPKhU (ORCPT ); Thu, 16 Jul 2009 06:37:20 -0400 Date: Thu, 16 Jul 2009 11:37:19 +0100 From: Mel Gorman To: KOSAKI Motohiro Cc: Andrew Morton , Ingo Molnar , linux-kernel@vger.kernel.org, Linux Memory Management List , Heinz Diehl , David Miller , Arnaldo Carvalho de Melo Subject: Re: [PATCH 2/3] profile: Suppress warning about large allocations when profile=1 is specified Message-ID: <20090716103719.GA22499@csn.ul.ie> References: <1247656992-19846-1-git-send-email-mel@csn.ul.ie> <1247656992-19846-3-git-send-email-mel@csn.ul.ie> <20090716100305.9D16.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20090716100305.9D16.A69D9226@jp.fujitsu.com> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2564 Lines: 74 On Thu, Jul 16, 2009 at 10:12:20AM +0900, KOSAKI Motohiro wrote: > > When profile= is used, a large buffer is allocated early at boot. This > > can be larger than what the page allocator can provide so it prints a > > warning. However, the caller is able to handle the situation so this patch > > suppresses the warning. > > I'm confused. > > Currently caller doesn't handle error return. > > ---------------------------------------------------------- > asmlinkage void __init start_kernel(void) > { > (snip) > init_timers(); > hrtimers_init(); > softirq_init(); > timekeeping_init(); > time_init(); > sched_clock_init(); > profile_init(); <-- ignore return value > ------------------------------------------------------------ > > and, if user want to use linus profiler, the user should choice select > proper bucket size by boot parameter. > Currently, allocation failure message tell user about specified bucket size > is wrong. > I think this patch hide it. > Look at what profile_init() itself is doing. You can't see it from the patch context but when alloc_pages_exact() fails, it calls vmalloc(). If that fails, profiling is just disabled. There isn't really anything the caller of profile_init() can do about it and the page allocator doesn't need to scream about it. > > > > > Signed-off-by: Mel Gorman > > --- > > kernel/profile.c | 5 +++-- > > 1 files changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/profile.c b/kernel/profile.c > > index 69911b5..419250e 100644 > > --- a/kernel/profile.c > > +++ b/kernel/profile.c > > @@ -117,11 +117,12 @@ int __ref profile_init(void) > > > > cpumask_copy(prof_cpu_mask, cpu_possible_mask); > > > > - prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL); > > + prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL|__GFP_NOWARN); > > if (prof_buffer) > > return 0; > > > > - prof_buffer = alloc_pages_exact(buffer_bytes, GFP_KERNEL|__GFP_ZERO); > > + prof_buffer = alloc_pages_exact(buffer_bytes, > > + GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN); > > if (prof_buffer) > > return 0; > > > -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/