From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1753574AbdKGTpm (ORCPT <rfc822;w@1wt.eu>);
        Tue, 7 Nov 2017 14:45:42 -0500
Received: from mail-io0-f169.google.com ([209.85.223.169]:43771 "EHLO
        mail-io0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1753049AbdKGTpk (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 7 Nov 2017 14:45:40 -0500
X-Google-Smtp-Source: ABhQp+Snbj+uqAWl+0HIpMFj2gu5QJcKFYXtBcLd0qzAAqhOmBykDC+r8mdn1WHwQu9BWyNSdTS5hQ==
Subject: Re: [PATCH V2] kthread: zero the kthread data structure
To: Shaohua Li <shli@fb.com>, LKML <linux-kernel@vger.kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Ingo Molnar <mingo@kernel.org>, Tejun Heo <tj@kernel.org>,
        Dmitry Vyukov <dvyukov@google.com>
References: <e00c78e6161ef7759a7e5f6abd2db84b9bcc8cf4.1510081552.git.shli@fb.com>
From: Jens Axboe <axboe@kernel.dk>
Message-ID: <cdd1e91b-941f-728d-6be0-34d4886e8d31@kernel.dk>
Date: Tue, 7 Nov 2017 12:45:38 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.4.0
MIME-Version: 1.0
In-Reply-To: <e00c78e6161ef7759a7e5f6abd2db84b9bcc8cf4.1510081552.git.shli@fb.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 11/07/2017 12:09 PM, Shaohua Li wrote:
> kthread() could bail out early before we initialize blkcg_css (if the
> kthread is killed very early. Please see xchg() statement in kthread()),
> which confuses free_kthread_struct. Instead of moving the blkcg_css
> initialization early, we simply zero the whole 'self' data structure,
> which doesn't sound much overhead.

Applied, thanks Shaohua.

-- 
Jens Axboe