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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 316CFC4332D for ; Wed, 17 Mar 2021 12:52:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DFFB964F67 for ; Wed, 17 Mar 2021 12:52:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229698AbhCQMwP (ORCPT ); Wed, 17 Mar 2021 08:52:15 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:36245 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229460AbhCQMvw (ORCPT ); Wed, 17 Mar 2021 08:51:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615985512; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=JFCqVw/Bnh39xL+6qMrjBQZdq8GZAVsRMv39uYKymdc=; b=cWr4/8ymKZq/pxn+WTD0fpw6xTYs5+/TLfnu/i7l6th8U9HVOBC6x90PdqNuVX/v2UmOUk ZZMAD2YyBVkUrOfrLcfl0YBSbS/VzI5sdXUZlJAZa+CdBXSXdJNu3+Humvo5eRU+ppOKtr BdAT/9RTK0sRhfy1gi+CqC4lCQLa3fk= Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-524-jBghUeHLN62u-DQEgxmrrA-1; Wed, 17 Mar 2021 08:51:50 -0400 X-MC-Unique: jBghUeHLN62u-DQEgxmrrA-1 Received: by mail-qt1-f200.google.com with SMTP id a16so9299065qtw.1 for ; Wed, 17 Mar 2021 05:51:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=JFCqVw/Bnh39xL+6qMrjBQZdq8GZAVsRMv39uYKymdc=; b=euyCE5rXx6insGKdoLTCnOJ61Mg/04ZsV3Wzq11MWhNqCyV+1t0I4xJmxwDWtrqKFl kDD8vxvIYO7xn9nhKuCyCf7UOZJ55k+Bk9/BuY3fz1c/tsLkIR7pHKU6RADACYrXisTx +pHHlkqUjvQaekRTcHGaPYPv2jDzQSJrQMN5lhrinXZps1MocZWoSdgO0kGihqUEwBWK kd0jsm65Pah/kqU4NFceLl21xDgPIFOzh4pCrZEH2aGmku+3RZCKjaCNgOFOOcZ7Q2nb sSZSxCIksSNMeS2hX8xMlW4O3ucsOqCQOvBU0+FPm4E+oLBOcO4x0vx9kHsuwUNUik6n HVTw== X-Gm-Message-State: AOAM532vcXrOCIjFOZZIGHne6NRKGdZyQ+4pDPyiQD6BWWuUEC/qdJ6d eoBVFArwfKCpphT3BB+KMwa1pKQH+juXjMo5mutAx1MtjlZeqc5FLUCjQAaZAKKa5va1Pu+zvsD DvOqnAoEbvybFqdtt7FxLabSYrfE= X-Received: by 2002:ac8:44aa:: with SMTP id a10mr4014979qto.146.1615985509644; Wed, 17 Mar 2021 05:51:49 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyjqRTvoCsN1i304riA8x6h0hmBBZlzasVHhUSH0QjVKjWIAllIZFcNmv7xRt0EBYP5OhAIZA== X-Received: by 2002:ac8:44aa:: with SMTP id a10mr4014963qto.146.1615985509377; Wed, 17 Mar 2021 05:51:49 -0700 (PDT) Received: from xz-x1 ([142.126.89.138]) by smtp.gmail.com with ESMTPSA id q65sm17169682qkb.51.2021.03.17.05.51.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Mar 2021 05:51:48 -0700 (PDT) Date: Wed, 17 Mar 2021 08:51:47 -0400 From: Peter Xu To: Daniel Wagner Cc: linux-rt-users@vger.kernel.org, John Kacur , Clark Williams , Daniel Wagner Subject: Re: [PATCH] rt-tests: Drop use_current_cpuset() check Message-ID: <20210317125147.GH395976@xz-x1> References: <20210315193707.359702-1-peterx@redhat.com> <20210316081826.bthxqja6shbcp36j@beryllium.lan> <20210316200705.GC395976@xz-x1> <20210317074903.5lskayjwylnvuhks@beryllium.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210317074903.5lskayjwylnvuhks@beryllium.lan> Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org Hi, Daniel, On Wed, Mar 17, 2021 at 08:49:03AM +0100, Daniel Wagner wrote: > On Tue, Mar 16, 2021 at 04:07:05PM -0400, Peter Xu wrote: > > I think what I'm missing is why we had such a restriction. Quotting from the > > commit ID: > > IIRC, the current behavior allows the process to be placed into a cgroup > with a subset of CPUs and you just can do 'cyclictest -a -t'. Process > should not ignore external configuration. That's my whole point here. In that case again I think a sane solution is not to check the cpu list in every single tool we use, because even if we do that for all tools in rt-teets repo, we can't guarantee to have this check for the rest tools to not ignore this restriction. A simple example is: what if the user specified "taskset -c $CPU cyclictest -a $CPU -t 1 ..." where $CPU is not in the allowed list of current bash? As long as the taskset would work the so-called "environment" will be changed before even loading cyclictest. If you see that's the point I said we should fail at the same check point of sched_setaffinity() rather than checking it explicitly in the tool, because if we want a real-world restriction that's the only place I think it's possible.. But I'm not a cgroup/container guy, please correct me if I understood. -- Peter Xu