From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [RFC PATCH-cgroup 5/6] cgroup: Skip dying css in cgroup_apply_control_{enable,disable} Date: Wed, 21 Jun 2017 18:04:38 -0400 Message-ID: <20170621220438.GB18600@htj.duckdns.org> References: <1497452737-11125-1-git-send-email-longman@redhat.com> <1497452737-11125-6-git-send-email-longman@redhat.com> <20170621214216.GE14720@htj.duckdns.org> <81c62822-8bb6-ae68-112a-dad49414e3f1@redhat.com> Mime-Version: 1.0 Return-path: 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=hdNaDUhRy38d7g69n77EmT5diJ/zh3aVBK6OeDO5VNk=; b=D9OFdnzViCJdFH9ptw9DO+tZnSUTEc36djp8An7UIUOAuGFjnhFBmgZIZiXdN4WLV6 vZVQbILN53kh540vKqyf7zhFQ7Y9vZScUnFBUqKx3KGV0vjIz+yXyluifMV2ErbmAqq4 uDyNhUBZp/aRFmgcyLl4j0GheH0PeanXR/tQgLRHZKGMcDJ+1BsGBIh/RHeKiFFsdmwm iolbqRVVMuaaUNVrPtLCtuS5V5Od/+r9kSLwOKdPj3GK7LQZ6SLflfFQ6uMahmPOkbjx A5VjYm+dI4GkSrW0MwK5m9DroKX6ysb9cJ5xc12RdbiA/YMsHUgr969YFAC4pbiPatzT BzSA== Content-Disposition: inline In-Reply-To: <81c62822-8bb6-ae68-112a-dad49414e3f1-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Waiman Long Cc: Li Zefan , Johannes Weiner , Peter Zijlstra , Ingo Molnar , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kernel-team-b10kYP2dOMg@public.gmane.org, pjt-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org, efault-Mmb7MZpHnFY@public.gmane.org, torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org Hello, On Wed, Jun 21, 2017 at 06:01:56PM -0400, Waiman Long wrote: > I do think that it can happen with existing code because CSS killing is > asynchronous, I think. So the command can complete before the CSS is > actually gone. If the next command to reactivate it happens fast enough, > we can trigger that. When I added more checking to my test script > essentially increasing the latency between successive tests, I couldn't > trigger it anymore. While disabling is asynchronous, there's a flushing logic before starting reenabling things, so the existing code shouldn't trigger that condition. But then there's should and the reality. :) Thanks. -- tejun