From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755783AbaCEQoF (ORCPT ); Wed, 5 Mar 2014 11:44:05 -0500 Received: from mx1.redhat.com ([209.132.183.28]:8657 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752109AbaCEQoE (ORCPT ); Wed, 5 Mar 2014 11:44:04 -0500 Date: Wed, 5 Mar 2014 17:12:27 +0100 From: Oleg Nesterov To: Khalid Aziz Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, peterz@infradead.org, akpm@linux-foundation.org, andi.kleen@intel.com, rob@landley.net, viro@zeniv.linux.org.uk, venki@google.com, linux-kernel@vger.kernel.org Subject: Re: [RFC] [PATCH] Pre-emption control for userspace Message-ID: <20140305161227.GA1713@redhat.com> References: <1393870033-31076-1-git-send-email-khalid.aziz@oracle.com> <20140304135624.GA6846@redhat.com> <53161116.9050109@oracle.com> <20140304190348.GA22075@redhat.com> <5316343B.2030404@oracle.com> <20140305143800.GA29480@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140305143800.GA29480@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/05, Oleg Nesterov wrote: > > You added /proc/sched_preempt_delay to avoid the syscall. I think it > would be better to simply add vdso_sched_preempt_delay() instead. I am stupid. vdso_sched_preempt_delay() obviously can't write to, say, task_struct. Oleg.