From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754128AbdKFQ3t (ORCPT ); Mon, 6 Nov 2017 11:29:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:44280 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754082AbdKFQ31 (ORCPT ); Mon, 6 Nov 2017 11:29:27 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3FE4C217C0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=chao@kernel.org Subject: Re: [PATCH 1/3] f2fs: avoid using __GFP_NOFAIL To: Michal Hocko Cc: jaegeuk@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Chao Yu References: <20171105135330.15070-1-chao@kernel.org> <20171106140853.f3nqwfg75tco67y6@dhcp22.suse.cz> <1434ded5-74f8-d5bf-1576-cca53a56144d@kernel.org> <20171106162303.syinckwdtdlwmeeg@dhcp22.suse.cz> From: Chao Yu Message-ID: Date: Tue, 7 Nov 2017 00:29:16 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <20171106162303.syinckwdtdlwmeeg@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/11/7 0:23, Michal Hocko wrote: > On Tue 07-11-17 00:08:25, Chao Yu wrote: > [...] >> BTW, I notice the comments of __GFP_NOFAIL, what does this mean? >> * Using this flag for costly allocations is _highly_ discouraged. > > This means that using __GFP_NOFAIL for high order allocations > (especially those with order > PAGE_ALLOC_COSTLY_ORDER) are highly > discouraged because we those are quite hard to get and looping inside > the allocator basically for ever is not a wise thing to do. That being > said replacing __GFP_NOFAIL by an open coded retry loop might make sense > for those e.g. to check signals or other termination conditions. Clear to me now, thanks for your explanation and review. :) Anyway, let me update this patch. Thanks, >