From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69A55C2D0DB for ; Wed, 22 Jan 2020 17:16:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E3A624673 for ; Wed, 22 Jan 2020 17:16:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="rMeSQ8cX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725883AbgAVRQe (ORCPT ); Wed, 22 Jan 2020 12:16:34 -0500 Received: from mail.efficios.com ([167.114.26.124]:33022 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725802AbgAVRQe (ORCPT ); Wed, 22 Jan 2020 12:16:34 -0500 Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id 0DB0925AF86; Wed, 22 Jan 2020 12:16:33 -0500 (EST) Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 4stJu28RmvV4; Wed, 22 Jan 2020 12:16:32 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id BA38C25AEA7; Wed, 22 Jan 2020 12:16:32 -0500 (EST) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com BA38C25AEA7 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1579713392; bh=9LMEjxtXO3DcVhBO+WK54vbQNVt6wfm87h8asYpsTpA=; h=Date:From:To:Message-ID:MIME-Version; b=rMeSQ8cXwgEJi10a+NrDWSJslrcR1JcaoqUB62X8OJYwp1iBoN1eQvqtcqcC01S+U lvt9z4hldAreTc3ggArc7tcmdi/v9l33zfVBieVm/sJ5OBB/xjrPVup+2I8C9z92KR jUYCOByauv7H6kHe5AIiOTkg7Yrf01Qxrzsw0ZI2PWiJzKHuAn2k4aOUzcHqSCrqd8 B+R6TGAAuwgZJ/Rcvbg/xxRfCzoSPWEF/YLwLlhUeo0ieRBOZ4LDjRFJqqiu6Ulm9s 2jLcjztV0a703bBxgymj8Iht3R0nVPVXAtKUMTDfTqnwPZC0Ri0cfFTiVWiUwqTzOr TXfiS6FaLkW2A== X-Virus-Scanned: amavisd-new at efficios.com Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id QUb4Vmo1dyGh; Wed, 22 Jan 2020 12:16:32 -0500 (EST) Received: from mail03.efficios.com (mail03.efficios.com [167.114.26.124]) by mail.efficios.com (Postfix) with ESMTP id 9F5B225AEA6; Wed, 22 Jan 2020 12:16:32 -0500 (EST) Date: Wed, 22 Jan 2020 12:16:32 -0500 (EST) From: Mathieu Desnoyers To: Jan Ziak <0xe2.0x9a.0x9b@gmail.com> Cc: Andi Kleen , Ben Maurer , Boqun Feng , Catalin Marinas , Chris Lameter , Dave Watson , "H. Peter Anvin" , Joel Fernandes , Josh Triplett , linux-api , linux-kernel , linux-kselftest , Russell King , Andy Lutomirski , Ingo Molnar , Michael Kerrisk , Paul , Peter Zijlstra , Paul Turner , rostedt , shuah , Thomas Gleixner , Will Deacon Message-ID: <1813399266.597377.1579713392568.JavaMail.zimbra@efficios.com> In-Reply-To: References: Subject: Re: [RFC PATCH v1] pin_on_cpu: Introduce thread CPU pinning system call MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [167.114.26.124] X-Mailer: Zimbra 8.8.15_GA_3895 (ZimbraWebClient - FF72 (Linux)/8.8.15_GA_3895) Thread-Topic: pin_on_cpu: Introduce thread CPU pinning system call Thread-Index: dvBLZ91ySDgPt1Gh4255dg7wp2uMvw== Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org (replying again as plain text for mailing lists) ----- On Jan 22, 2020, at 10:44 AM, Jan Ziak 0xe2.0x9a.0x9b@gmail.com wrote: > Hello > I would like to note that this does not help userspace to express dynamic > scheduling relationships among processes/threads such as "do not run processes > A and B on the same core" or "run processes A and B on cores sharing the same > L2 cache". Indeed, this is not what this system call is trying to solve. Does the name "pin_on_cpu" lead to confusion here ? I thought that cgroups was already the mechanism taking care of this kind of requirement. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com