From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6968EC2D0F4 for ; Wed, 1 Apr 2020 07:10:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1DD202071A for ; Wed, 1 Apr 2020 07:10:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1DD202071A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id ACD026B000C; Wed, 1 Apr 2020 03:10:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A4C2A6B000D; Wed, 1 Apr 2020 03:10:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6066E6B006C; Wed, 1 Apr 2020 03:10:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0061.hostedemail.com [216.40.44.61]) by kanga.kvack.org (Postfix) with ESMTP id 331F86B000C for ; Wed, 1 Apr 2020 03:10:03 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D1F7A180ACF62 for ; Wed, 1 Apr 2020 07:10:02 +0000 (UTC) X-FDA: 76658411844.24.cows81_61580b1d417 X-HE-Tag: cows81_61580b1d417 X-Filterd-Recvd-Size: 3432 Received: from mail-wm1-f67.google.com (mail-wm1-f67.google.com [209.85.128.67]) by imf37.hostedemail.com (Postfix) with ESMTP for ; Wed, 1 Apr 2020 07:10:02 +0000 (UTC) Received: by mail-wm1-f67.google.com with SMTP id t8so1972397wmi.2 for ; Wed, 01 Apr 2020 00:10:02 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=tKcCvBkl/5wFmhqyWXdNyuguB+1XgXDUmUQ8zhlCfl0=; b=aEA4qy5o9Lk5CfZb7BYWB++hl1meK+yXKNbzqkswKffqX/GJ6ldFs3OB8z8qHS1KXC S2LxUp0FyR8bHcV0SeH5txtnrnosVz3lYtj9FdiwiXao/P3O6wvcm9Ybb+Yx0Y+y7FVI 9Boe1uDJas6P/NE8dv0AUTWpFBAxO4omsOLdgolReSw4K54WBwUZ4Vytk/JZN0JRjZJr 3IZ0ABxfJMgHagNljFz70QKjgqTNqrn28+7SFEQLGei4JwZcUeUW8tnE858QVIDvyw1c 8/5dMzBRxZAC3S1AgtbneH2EjCmkBW5ct6Rhf5dMeMUn/RmVGJvp/kmct51NCJDoAKLv 9eDQ== X-Gm-Message-State: AGi0PubaNwOdo2/T03ruvW/ksvplfQMnNynCRixzx9gGSociPyasCV0X WmNfcDbgYqhbEpnTec7P04Y= X-Google-Smtp-Source: APiQypJKzF9JIQqbmrZ1L+OJq9oATJtUV+U+TwMIOVFC0ButeSV7aj/VbyF6MRit5GbMNX5BdI0M+Q== X-Received: by 2002:a7b:cb59:: with SMTP id v25mr2931801wmj.13.1585725001425; Wed, 01 Apr 2020 00:10:01 -0700 (PDT) Received: from localhost (ip-37-188-180-223.eurotel.cz. [37.188.180.223]) by smtp.gmail.com with ESMTPSA id f141sm1517974wmf.3.2020.04.01.00.09.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Apr 2020 00:10:00 -0700 (PDT) Date: Wed, 1 Apr 2020 09:09:58 +0200 From: Michal Hocko To: Uladzislau Rezki Cc: Joel Fernandes , linux-kernel@vger.kernel.org, linux-mm@kvack.org, rcu@vger.kernel.org, willy@infradead.org, peterz@infradead.org, neilb@suse.com, vbabka@suse.cz, mgorman@suse.de, Andrew Morton , Josh Triplett , Lai Jiangshan , Mathieu Desnoyers , "Paul E. McKenney" , Steven Rostedt Subject: Re: [PATCH RFC] rcu/tree: Use GFP_MEMALLOC for alloc memory to free memory pattern Message-ID: <20200401070958.GB22681@dhcp22.suse.cz> References: <20200331131628.153118-1-joel@joelfernandes.org> <20200331145806.GB236678@google.com> <20200331153450.GM30449@dhcp22.suse.cz> <20200331161215.GA27676@pc636> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200331161215.GA27676@pc636> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue 31-03-20 18:12:15, Uladzislau Rezki wrote: > > > > __GFP_ATOMIC | __GFP_HIGH is the way to get an additional access to > > memory reserves regarless of the sleeping status. > > > Michal, just one question here regarding proposed flags. Can we also > tight it with __GFP_RETRY_MAYFAIL flag? Means it also can repeat a few > times in order to increase the chance of being success. yes, __GFP_RETRY_MAYFAIL is perfectly valid with __GFP_ATOMIC. Please note that __GFP_ATOMIC, despite its name, doesn't imply an atomic allocation which cannot sleep. Quite confusing, I know. A much better name would be __GFP_RESERVES or something like that. -- Michal Hocko SUSE Labs