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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham 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 0F8F5C43381 for ; Fri, 8 Mar 2019 07:22:54 +0000 (UTC) Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B959620684 for ; Fri, 8 Mar 2019 07:22:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=kroah.com header.i=@kroah.com header.b="QKzVKmBl"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="vTdotqvM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B959620684 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kroah.com Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=kernelnewbies-bounces@kernelnewbies.org Received: from localhost ([::1] helo=shelob.surriel.com) by shelob.surriel.com with esmtp (Exim 4.91) (envelope-from ) id 1h29pO-0005Fl-FF; Fri, 08 Mar 2019 02:21:58 -0500 Received: from out2-smtp.messagingengine.com ([66.111.4.26]) by shelob.surriel.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91) (envelope-from ) id 1h29pM-0005Ff-2q for kernelnewbies@kernelnewbies.org; Fri, 08 Mar 2019 02:21:56 -0500 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id 9F6D7220DE; Fri, 8 Mar 2019 02:21:54 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute6.internal (MEProxy); Fri, 08 Mar 2019 02:21:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm3; bh=daDAQKlXhEG99ndQN3KIxmfjshI mU1LHtYLRM92l9xQ=; b=QKzVKmBl+0B7UpHNHmqcXB9XEGHKmPpPfc9VrsL9vfp d1VhpIELlrmkd0CIqcfm42c7TLMPfJ3XgfVhLenTfqjxqyl4t9RIR/NQ0SCxac0T LTJW5HqkfKbQNJCP6CTqWy90YOjzSp5BTqbTnpqCoX79aMepN5WyPOfOQDzI2PGc fvn0imojnhEavJ2BV+snxW9qieHNf7iXyg54BvXuAQh0KVgtOSbOtr3X5+7GAHIr YbPfVQywoEvHJtfbfgM+frpv53LTYDg451UxnBL6M5pGwZ0U2SrTFV2ViUc+0pxr 7EfzGL5wsOF/Wn8lxSSjNj+8KRDYfLvkoGiWjJfrJxg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=daDAQK lXhEG99ndQN3KIxmfjshImU1LHtYLRM92l9xQ=; b=vTdotqvMtdNunWvWqBpaUW OohBBQi1WW01UNRj5SnHeKc0XALLEdgVf0OsoZc44ilkPHqmxHFUaUHadcrD4bjN J1if1Jyy1SJiaSOlom1ygm8WJKhT/1uLXcbc9HYUZIXjCKOPqG3whskJh3/+iTpD NS+gSAtbydiMLsxCYLrIRIESOwrvkhxFrd/l+yaCebE0HkSV7qTi1H8sXHmOsNlH Hf8t4Uz15dNl2NIYEF2mHG59pu69D8ZOtTFCpb3fb9aQkcY0Sk5LM+nr+a//mSaM q4GN1szdT0mGMqyubKNLQm+6+8dcMXOpd04BX2qAPFdQBOb1o++KS34Km+2Uf3Tg == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedutddrfeelgddutddvucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpeffhffvuffkfhggtggujggfsehttd ertddtredvnecuhfhrohhmpefirhgvghcumffjuceoghhrvghgsehkrhhorghhrdgtohhm qeenucfkphepkeefrdekiedrkeelrddutdejnecurfgrrhgrmhepmhgrihhlfhhrohhmpe hgrhgvgheskhhrohgrhhdrtghomhenucevlhhushhtvghrufhiiigvpedu X-ME-Proxy: Received: from localhost (5356596b.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) by mail.messagingengine.com (Postfix) with ESMTPA id 90DF210319; Fri, 8 Mar 2019 02:21:53 -0500 (EST) Date: Fri, 8 Mar 2019 08:21:52 +0100 From: Greg KH To: wuzhouhui Subject: Re: How to avoid or reduce GFP_ATOMIC allocation failed Message-ID: <20190308072152.GA10654@kroah.com> References: <51af9230.9ed2.1695bce6545.Coremail.wuzhouhui14@mails.ucas.ac.cn> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <51af9230.9ed2.1695bce6545.Coremail.wuzhouhui14@mails.ucas.ac.cn> User-Agent: Mutt/1.11.3 (2019-02-01) Cc: kernelnewbies@kernelnewbies.org X-BeenThere: kernelnewbies@kernelnewbies.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Learn about the Linux kernel List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kernelnewbies-bounces@kernelnewbies.org On Fri, Mar 08, 2019 at 01:37:26PM +0800, wuzhouhui wrote: > Hi, > > I check kernel code and found that GFP_ATOMIC allocation will > use emergency pool and maybe failed if emergency pool is not > enough. And GFP_ATOMIC doesn't trigger reclaim (because of > ATOMIC) even if there are a lot of page caches. So my question > is how to avoid or reduce GFP_ATOMIC allocation failed if there > are enough reclaimable memory? Is there some kernel parameters > can be configured? Have you seen the ATOMIC pools be used up and not able to be reclaimed in real-world usages? If so, I'm sure the mm developers would love to hear from you about this as I really do not think that is a situation that can happen easily, if at all. And no, I do not think there are any such parameters, the kernel should be self-tuning for things like this. thanks, greg k-h _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies