From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [PATCH, v6 3/3] cgroups: introduce timer slack controller Date: Tue, 15 Feb 2011 07:04:00 +0100 (CET) Message-ID: References: <1297688787-3592-1-git-send-email-kirill@shutemov.name> <1297688787-3592-4-git-send-email-kirill@shutemov.name> <20110214151914.GA4210@shutemov.name> <20110214223939.GA6230@shutemov.name> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <20110214223939.GA6230-oKw7cIdHH8eLwutG50LtGA@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Kirill A. Shutemov" Cc: Paul Menage , Li Zefan , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, Arjan van de Ven , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Matt Helsley , Andrew Morton , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-api@vger.kernel.org On Tue, 15 Feb 2011, Kirill A. Shutemov wrote: > On Mon, Feb 14, 2011 at 06:01:06PM +0100, Thomas Gleixner wrote: > > > I think silent change here is wrong. cpuset returns -EBUSY in similar > > > case. > > > > And how is cpuset relevant for this ? Not at all. This is about > > timer_slack and we better have a well defined scheme for all of this > > and not some cobbled together thing with tons of exceptions and corner > > cases. Of course undocumented as far the code goes. > > I don't like silent cascade changes. Userspace can implement it if > needed. -EBUSY is appropriate. And I don't like totally uncommented code which follows come cobbled together completely non obvious rules. It's not about what you like. It's about getting useful functionality when we add a new infrastructure like this. So could you please explain what the rules of updating are, so that a reviewer has a chance to understand the rationale of all this. Thanks, tglx