From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763219Ab3DCJ1G (ORCPT ); Wed, 3 Apr 2013 05:27:06 -0400 Received: from cantor2.suse.de ([195.135.220.15]:58439 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763202Ab3DCJ1C (ORCPT ); Wed, 3 Apr 2013 05:27:02 -0400 Date: Wed, 3 Apr 2013 11:26:59 +0200 From: Jan Kara To: Tejun Heo Cc: axboe@kernel.dk, akpm@linux-foundation.org, jack@suse.cz, david@fromorbit.com, linux-kernel@vger.kernel.org, Oleg Nesterov Subject: Re: [PATCH 1/3] kthread: implement probe_kthread_data() Message-ID: <20130403092659.GE7999@quack.suse.cz> References: <1364612447-6810-1-git-send-email-tj@kernel.org> <1364612447-6810-2-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1364612447-6810-2-git-send-email-tj@kernel.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 29-03-13 20:00:45, Tejun Heo wrote: > Implement probe_kthread_data() which returns kthread_data if > accessible. The function is equivalent to kthread_data() except that > the specified @task may not be a kthread or its vfork_done is already > cleared rendering struct kthread inaccessible. In the former case, > probe_kthread_data() may return any value. In the latter, NULL. > > This will be used to safely print debug information without affecting > synchronization in the normal paths. Workqueue debug info printing on > dump_stack() and friends will make use of it. Thanks for looking into this. Just one typo correction below: > @@ -122,6 +123,24 @@ void *kthread_data(struct task_struct *task) > return to_kthread(task)->data; > } > > +/** > + * probe_kthread_data - speculatively version of kthread_data() ^^^^ speculative Honza -- Jan Kara SUSE Labs, CR