From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754817AbZHCTzh (ORCPT ); Mon, 3 Aug 2009 15:55:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754712AbZHCTzg (ORCPT ); Mon, 3 Aug 2009 15:55:36 -0400 Received: from smtp-out.google.com ([216.239.45.13]:20799 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754641AbZHCTzg convert rfc822-to-8bit (ORCPT ); Mon, 3 Aug 2009 15:55:36 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:content-transfer-encoding:x-system-of-record; b=c46pVEQBDdrBZqLhUxzWAmk/wdlP/1T9TpMGuEb8mGKLmiESqHnCoG/Xgb21o5A56 j2NTyhTbHbtYvo/sqaVQw== MIME-Version: 1.0 In-Reply-To: <20090803194555.GA10158@us.ibm.com> References: <20090731012908.27908.62208.stgit@hastromil.mtv.corp.google.com> <20090731015154.27908.9639.stgit@hastromil.mtv.corp.google.com> <20090803175452.GA5481@us.ibm.com> <2f86c2480908031113y525b6cbdhe418b8a0364c7760@mail.gmail.com> <20090803185556.GA8469@us.ibm.com> <20090803194555.GA10158@us.ibm.com> Date: Mon, 3 Aug 2009 12:55:33 -0700 Message-ID: <6599ad830908031255j68ce047x7165bfefa62ed53c@mail.gmail.com> Subject: Re: [PATCH 6/6] Makes procs file writable to move all threads by tgid at once From: Paul Menage To: "Serge E. Hallyn" Cc: Benjamin Blum , containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 3, 2009 at 12:45 PM, Serge E. Hallyn wrote: > > This is probably a stupid idea, but...  what about having zero > overhead at clone(), and instead, at cgroup_task_migrate(), > dequeue_task()ing all of the affected threads for the duration of > the migrate? That doesn't sound too unreasonable, actually - it would certainly simplify things a fair bit. Is there a standard API for doing that? dequeue_task() itself doesn't really look like a public API. I guess that the task freezer would be one way to accomplish this? I can imagine that the set of people who'd complain about the latency hit when migrating with your solution would be smaller than the people who'd complain about the increased overhead in the normal clone case. Paul