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_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 62FB9C3A5A8 for ; Wed, 4 Sep 2019 07:43:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2256F23400 for ; Wed, 4 Sep 2019 07:43:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="lCya9oPW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2256F23400 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BA9636B0003; Wed, 4 Sep 2019 03:43:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B31506B0006; Wed, 4 Sep 2019 03:43:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9F8A46B0007; Wed, 4 Sep 2019 03:43:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0223.hostedemail.com [216.40.44.223]) by kanga.kvack.org (Postfix) with ESMTP id 7747E6B0003 for ; Wed, 4 Sep 2019 03:43:18 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 0D09C180AD819 for ; Wed, 4 Sep 2019 07:43:18 +0000 (UTC) X-FDA: 75896447676.21.wing98_912c9fbc2b13a X-HE-Tag: wing98_912c9fbc2b13a X-Filterd-Recvd-Size: 4166 Received: from mail-pl1-f195.google.com (mail-pl1-f195.google.com [209.85.214.195]) by imf27.hostedemail.com (Postfix) with ESMTP for ; Wed, 4 Sep 2019 07:43:17 +0000 (UTC) Received: by mail-pl1-f195.google.com with SMTP id gn20so9190097plb.2 for ; Wed, 04 Sep 2019 00:43:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Qj+DAxsSIX3ZqKCcNj9WFrsINQyctNKm0DapU8GePMg=; b=lCya9oPWLL6Z2sCvMqFx61guCAYb06hPqKEzeto7EkIbJJkzeWfSzu7uAmnoTtP8ml xwSSllg+7Cg/uFNKX3vW16GYIPDhCkAmstIR4IRc7GPm9D3jCJl1sgbuWkmzesSTQa1k VJyOgK5+Mv7W53iq0EhizOvaAZvrpzkaEotfxKWSziTRO3SQwvKiakik9sZQSga92v12 CF8lOSfMAKCJw8Qxi7kpK3/tCDkU3CULfpbAp+Lj3IGZp+WZtzlPfFHzYLA1zDI9nhXY hxsUV472mag4UDl6Vv5Go5942fXu/+UV8xMWd9JR43SMVyF30BYgkHYkcg/JrLxHLCR7 mUeg== 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:user-agent; bh=Qj+DAxsSIX3ZqKCcNj9WFrsINQyctNKm0DapU8GePMg=; b=s79Rc7WGLU8sWIld2ndOGWIfTbTQ2q8Tx/WGqi5nGmikhJzK1BqOwwa56UZ+G2o0HO vq6Z59c6BQPJXks2h6+otvRBwAEH/QyFZyIhqSg7uB2dNUkcv6WPrZTfXnxTQoj+vwQh fzKIeMnxZEBhGLE8Q85DZxBImIzsaMoDjsrlWcu3+gFeh2sBm2cWbir/1HrtqdTl43pP 2VYziRHI6zP3DSFj0oXAv22ChALBEZxnMaCY1uciH2do2yYbZJf47AZPMuWVLtMt6Vom WGZwh9zESSZaS01OSz7vcILCtR3uZVMbzGyVIn0Wrh3FhklRzapDXxHLOKlfILg+sVpY vFsA== X-Gm-Message-State: APjAAAUXHAeI9I28VoGwZhOIrWTVTjLwFYKhOmOlZDHxiKE/1YfahN9f OsAhkCuAvMuv2bTRpBGd8h0= X-Google-Smtp-Source: APXvYqwf8YuF18rL+t+nFsRll+w6Tgkdib8E7Z6IJLldxGfK/Upkt0ST6okY6POe2h+lSN5PdkHtzw== X-Received: by 2002:a17:902:6b88:: with SMTP id p8mr38148119plk.95.1567582996648; Wed, 04 Sep 2019 00:43:16 -0700 (PDT) Received: from localhost ([175.223.23.37]) by smtp.gmail.com with ESMTPSA id c6sm14214884pgd.66.2019.09.04.00.43.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Sep 2019 00:43:15 -0700 (PDT) Date: Wed, 4 Sep 2019 16:43:12 +0900 From: Sergey Senozhatsky To: Michal Hocko Cc: Qian Cai , Eric Dumazet , davem@davemloft.net, netdev@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Petr Mladek , Sergey Senozhatsky , Steven Rostedt Subject: Re: [PATCH] net/skbuff: silence warnings under memory pressure Message-ID: <20190904074312.GA25744@jagdpanzerIV> References: <1567178728.5576.32.camel@lca.pw> <229ebc3b-1c7e-474f-36f9-0fa603b889fb@gmail.com> <20190903132231.GC18939@dhcp22.suse.cz> <1567525342.5576.60.camel@lca.pw> <20190903185305.GA14028@dhcp22.suse.cz> <1567546948.5576.68.camel@lca.pw> <20190904061501.GB3838@dhcp22.suse.cz> <20190904064144.GA5487@jagdpanzerIV> <20190904065455.GE3838@dhcp22.suse.cz> <20190904071911.GB11968@jagdpanzerIV> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190904071911.GB11968@jagdpanzerIV> User-Agent: Mutt/1.12.1 (2019-06-15) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000018, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On (09/04/19 16:19), Sergey Senozhatsky wrote: > Hmm. I need to look at this more... wake_up_klogd() queues work only once > on particular CPU: irq_work_queue(this_cpu_ptr(&wake_up_klogd_work)); > > bool irq_work_queue() > { > /* Only queue if not already pending */ > if (!irq_work_claim(work)) > return false; > > __irq_work_queue_local(work); > } Plus one more check - waitqueue_active(&log_wait). printk() adds pending irq_work only if there is a user-space process sleeping on log_wait and irq_work is not already scheduled. If the syslog is active or there is noone to wakeup then we don't queue irq_work. -ss