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=-5.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 8BEFCC67863 for ; Tue, 23 Oct 2018 19:58:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5075820671 for ; Tue, 23 Oct 2018 19:58:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="nqaiSjv4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5075820671 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728608AbeJXEXo (ORCPT ); Wed, 24 Oct 2018 00:23:44 -0400 Received: from mail-yw1-f65.google.com ([209.85.161.65]:46307 "EHLO mail-yw1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725740AbeJXEXo (ORCPT ); Wed, 24 Oct 2018 00:23:44 -0400 Received: by mail-yw1-f65.google.com with SMTP id j202-v6so1070701ywa.13; Tue, 23 Oct 2018 12:58:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=gdSq9bF0nedG9Ber+aOH1to6mh30wA2VJb0a3wsWazw=; b=nqaiSjv40eEZfi2hLDuh+E0hMknzXjzR3nElOJYcdjE7GLcbrhJTsAXifLlqGi5Z/O WVfxCKSV2x4CfGZqUw7BQd6b8Kfk7PLQR5X9rNIno+SWjg91tBV/WyNJBcX+HuvLE5UZ SPUHkXstZtcE7UExcHviwr39MGKM2T8bZiXmITfFeLAVN2sOuHhR1M8CQjTyGmtIZWLS n5tqJpkw24cQMGg+g6ohFIi2Oz+zfe/spdwj4shrq8/ohevq9ecSBh4WUpDrlXFxTpo1 eeUiGUTlrFVF/2wNFwmjQa7RvAkt6eYHIZpczABgZe7+e2gvrLGUaSo5RToGURIVBJ10 ogbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=gdSq9bF0nedG9Ber+aOH1to6mh30wA2VJb0a3wsWazw=; b=BfQBBDoY7qmGZSlulN+0NQxp9SQCXyLpROlvNdUNK82b/r9EcmNm1NmInYq3Z7g7VX 9iKOWDe+ug/+rvLAU/K341zZKkKq4W73qs2N5060Dsgt8Vm/rzefB68edOY1qSMhYpnN ItaRhOVqDM46LfBpk9kJvdURAhGo8vkTG/+mkkVsVN2QgUXR6uut2M/flAlqyRc4LUtc 0YtAzvTiHLwVlQ9SQIxK0wNbscRWRbDWAF5tqXiW7M1/SBvIFqJ/O1FISd9GBRSImZ9w rZycT+Nsnbi/laU7HJmOpHJmhdgi6POb8Mkll/kQs2vM4OyZ+LYR6KwbrNXpKI/iYsaB X5EA== X-Gm-Message-State: ABuFfoisExXFDGIkw+KPlraRhOdyTbZwKTVXUDhWrYdckEGJ+U7J73Rv A1beShSv9P8+i9T0o4kbOmQ= X-Google-Smtp-Source: ACcGV63XAvBMtpgMSK+JKA7OFDeb8E9GexggZvQ5vUg7oyO+IWw+PpVYwziT3KZJJT1CeURTGWmSAA== X-Received: by 2002:a0d:f546:: with SMTP id e67-v6mr36951858ywf.304.1540324731577; Tue, 23 Oct 2018 12:58:51 -0700 (PDT) Received: from localhost ([2620:10d:c091:180::1:c0bc]) by smtp.gmail.com with ESMTPSA id 80-v6sm1162072ywh.55.2018.10.23.12.58.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 23 Oct 2018 12:58:50 -0700 (PDT) Date: Tue, 23 Oct 2018 12:58:48 -0700 From: Tejun Heo To: Michal Hocko Cc: "David S. Miller" , Johannes Weiner , cgroups@vger.kernel.org, netdev@vger.kernel.org, LKML , Michal Hocko Subject: Re: [RFC PATCH] cgroup, netclassid: add a preemption point to write_classid Message-ID: <20181023195848.GC4182586@devbig004.ftw2.facebook.com> References: <20181018085617.28456-1-mhocko@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181018085617.28456-1-mhocko@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 18, 2018 at 10:56:17AM +0200, Michal Hocko wrote: > From: Michal Hocko > > We have seen a customer complaining about soft lockups on !PREEMPT > kernel config with 4.4 based kernel ... > If a cgroup has many tasks with many open file descriptors then we would > end up in a large loop without any rescheduling point throught the > operation. Add cond_resched once per task. > > Signed-off-by: Michal Hocko Applied to cgroup/for-4.20. Thanks. -- tejun