From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] device_cgroup: don't grab mutex in rcu callback Date: Wed, 23 Jan 2013 09:18:54 -0800 Message-ID: <20130123171854.GD2373@mtj.dyndns.org> References: <1358961426-8482-1-git-send-email-jerry.snitselaar@oracle.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:sender:date:from:to:cc:subject:message-id:references :mime-version:content-type:content-disposition:in-reply-to :user-agent; bh=mFEJPcxiBVCmgDiRI7WI06KKOIvIWhzKfSa+hXdLOnQ=; b=EDvK1+oL7ETn9GWEL2MRWSvjk9ojdn5aKlnDU7jX2BmS7TeejR31cWXDTCzmgQQrko /DM9k7S6NmedU6urb83a+j4x8M7vnaUmleR1bVib1eEP4xQETIz0sCC0HzqUQGmJM8x7 XLjepuLMJQIMn10N/AezA+cBO5nZHEyzlE0R9/2xB0ZYXAssRtMaBn+Z0MaN05AoeE17 is6M7TWVOfHqR6VaIBdBEBnQwzTVquvI0JHb5PDyYtYtGfnaiLZXVGXXTAI7k+AGpvt8 GJl7LVqmcpmV6bi61gylr8pwYvtwfWUjWY5otH9dA/FalO/g+yf2Bq2u97C/vGZrjlRS x+1Q== Content-Disposition: inline In-Reply-To: <1358961426-8482-1-git-send-email-jerry.snitselaar-QHcLZuEGTsvQT0dZR+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: Jerry Snitselaar Cc: aris-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On Wed, Jan 23, 2013 at 10:17:06AM -0700, Jerry Snitselaar wrote: > commit 103a197 "security/device_cgroup: lock assert fails in > dev_exception_clean()" grabs devcgroup_mutex to fix assert failure, > but mutex can't be grabbed in rcu callback. Since there shouldn't be > any other references when css_free is called, mutex isn't needed for > list cleanup in devcgroup_css_free(). > > Signed-off-by: Jerry Snitselaar Acked-by: Tejun Heo -- tejun