From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755162AbaCERKz (ORCPT ); Wed, 5 Mar 2014 12:10:55 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:41622 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751879AbaCERKx (ORCPT ); Wed, 5 Mar 2014 12:10:53 -0500 Message-ID: <53175A73.2070204@oracle.com> Date: Wed, 05 Mar 2014 10:10:11 -0700 From: Khalid Aziz Organization: Oracle Corp User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: Oleg Nesterov 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 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> <20140305161227.GA1713@redhat.com> In-Reply-To: <20140305161227.GA1713@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/05/2014 09:12 AM, Oleg Nesterov wrote: > 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. > That is easy to miss :) I had looked into vdso when I started but found out I can't use vdso for this. -- Khalid