From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [RFC -v2 PATCH 2/3] sched: add yield_to function Date: Sat, 18 Dec 2010 19:08:15 +0200 Message-ID: <4D0CEA7F.9080603@redhat.com> References: <20101213224434.7495edb2@annuminas.surriel.com> <20101213224657.7e141746@annuminas.surriel.com> <1292306896.7448.157.camel@marge.simson.net> <4D0A6D34.6070806@redhat.com> <1292569018.7772.75.camel@marge.simson.net> <1292570143.7772.84.camel@marge.simson.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Rik van Riel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Srivatsa Vaddagiri , Peter Zijlstra , Chris Wright To: Mike Galbraith Return-path: In-Reply-To: <1292570143.7772.84.camel@marge.simson.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 12/17/2010 09:15 AM, Mike Galbraith wrote: > BTW, with this vruntime donation thingy, what prevents a task from > forking off accomplices who do nothing but wait for a wakeup and > yield_to(exploit)? > What's the difference between that and forking off accomplices who run(exploit) directly? Many threads dominating the scheduler has been solved by group scheduling. We need to make sure directed yield doesn't violate that, but I don't see new problems. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.