From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f200.google.com (mail-qk0-f200.google.com [209.85.220.200]) by kanga.kvack.org (Postfix) with ESMTP id 9ABEE831F4 for ; Thu, 18 May 2017 11:56:43 -0400 (EDT) Received: by mail-qk0-f200.google.com with SMTP id v195so17268918qka.1 for ; Thu, 18 May 2017 08:56:43 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id z51si5865508qtz.214.2017.05.18.08.56.42 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 18 May 2017 08:56:42 -0700 (PDT) Subject: Re: [RFC PATCH v2 09/17] cgroup: Keep accurate count of tasks in each css_set References: <1494855256-12558-1-git-send-email-longman@redhat.com> <1494855256-12558-10-git-send-email-longman@redhat.com> <20170517214034.GF942@htj.duckdns.org> From: Waiman Long Message-ID: Date: Thu, 18 May 2017 11:56:38 -0400 MIME-Version: 1.0 In-Reply-To: <20170517214034.GF942@htj.duckdns.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tejun Heo Cc: Li Zefan , Johannes Weiner , Peter Zijlstra , Ingo Molnar , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, kernel-team@fb.com, pjt@google.com, luto@amacapital.net, efault@gmx.de On 05/17/2017 05:40 PM, Tejun Heo wrote: > Hello, > > On Mon, May 15, 2017 at 09:34:08AM -0400, Waiman Long wrote: >> The reference count in the css_set data structure was used as a >> proxy of the number of tasks attached to that css_set. However, that >> count is actually not an accurate measure especially with thread mode >> support. So a new variable task_count is added to the css_set to keep >> track of the actual task count. This new variable is protected by >> the css_set_lock. Functions that require the actual task count are >> updated to use the new variable. >> >> Signed-off-by: Waiman Long > Looks good. We probably should replace css_set_populated() to use > this too. > > Thanks. > Yes, you are right. css_set_populated() can be replaced with a check on the task_count. Regards, Longman -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org