From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1753919AbbH0JSZ (ORCPT <rfc822;w@1wt.eu>);
	Thu, 27 Aug 2015 05:18:25 -0400
Received: from mx2.suse.de ([195.135.220.15]:47530 "EHLO mx2.suse.de"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1751444AbbH0JSV (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Thu, 27 Aug 2015 05:18:21 -0400
Subject: Re: [PATCH 07/12] mm, page_alloc: Distinguish between being unable to
 sleep, unwilling to sleep and avoiding waking kswapd
To: Mel Gorman <mgorman@techsingularity.net>
References: <1440418191-10894-1-git-send-email-mgorman@techsingularity.net>
 <1440418191-10894-8-git-send-email-mgorman@techsingularity.net>
 <55DC8BD7.602@suse.cz> <20150826144533.GO12432@techsingularity.net>
 <55DDE842.8000103@suse.cz> <20150826181041.GR12432@techsingularity.net>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Johannes Weiner <hannes@cmpxchg.org>, Rik van Riel <riel@redhat.com>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>, Michal Hocko <mhocko@kernel.org>,
        Linux-MM <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>
From: Vlastimil Babka <vbabka@suse.cz>
Message-ID: <55DED5D9.8@suse.cz>
Date: Thu, 27 Aug 2015 11:18:17 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Thunderbird/38.2.0
MIME-Version: 1.0
In-Reply-To: <20150826181041.GR12432@techsingularity.net>
Content-Type: text/plain; charset=iso-8859-15; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 08/26/2015 08:10 PM, Mel Gorman wrote:
>>
>> I think the most robust check would be to rely on what was already prepared
>> by gfp_to_alloc_flags(), instead of repeating it here. So add alloc_flags
>> parameter to warn_alloc_failed(), and drop the filter when
>> - ALLOC_CPUSET is not set, as that disables the cpuset checks
>> - ALLOC_NO_WATERMARKS is set, as that allows calling
>>    __alloc_pages_high_priority() attempt which ignores cpusets
>>
>
> warn_alloc_failed is used outside of page_alloc.c in a context that does
> not have alloc_flags. It could be extended to take an extra parameter
> that is ALLOC_CPUSET for the other callers or else split it into
> __warn_alloc_failed (takes alloc_flags parameter) and warn_alloc_failed
> (calls __warn_alloc_failed with ALLOC_CPUSET) but is it really worth it?

Probably not. Testing lack of __GFP_DIRECT_RECLAIM is good enough until 
somebody cares more.