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=-9.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 01045C4363A for ; Fri, 23 Oct 2020 13:25:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5CE520878 for ; Fri, 23 Oct 2020 13:25:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="1Jpp6aUe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S464719AbgJWNZU (ORCPT ); Fri, 23 Oct 2020 09:25:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47824 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S373829AbgJWNZU (ORCPT ); Fri, 23 Oct 2020 09:25:20 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68244C0613CE; Fri, 23 Oct 2020 06:25:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=HEsMZW6VUzWZDcaTQFGuaqHUigGcMc17DOxpKIiHD3U=; b=1Jpp6aUef3ZNl/fpS536OWGOTZ o4VHLn/1/CVcI3hsGyiAlldbrSaHH2Lp77z1BHDLPXCLVbzr1mpe0ipzTm/4LMjybDReOxC4EDnlH u6SbYBUdzmxNxCGNGnTJVdm5/Z4YYYqmzwfry8pZe+iGi/kkIaUy0znCaDb4znXBwIribIVwzXimD wwBgnxpZPWjcY6TCzbi7mqeGtvDQA6SNvqCQ2zwj6z/ofQ78mowl1FYn/+6Rr0neaIpw4u8aoZlcU IPdVcpZuEx4u8wBKya8J++OLqHQUrCQqsVQILjky4/t3vj7hixqUguwYEku8yPWZwddAtOOU6/8XA um4xU4Qw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kVx47-00026G-SL; Fri, 23 Oct 2020 13:25:08 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id BDEE8300B22; Fri, 23 Oct 2020 15:25:05 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id AD9C023268B98; Fri, 23 Oct 2020 15:25:05 +0200 (CEST) Date: Fri, 23 Oct 2020 15:25:05 +0200 From: Peter Zijlstra To: Nitesh Narayan Lal Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-pci@vger.kernel.org, intel-wired-lan@lists.osuosl.org, frederic@kernel.org, mtosatti@redhat.com, sassmann@redhat.com, jesse.brandeburg@intel.com, lihong.yang@intel.com, helgaas@kernel.org, jeffrey.t.kirsher@intel.com, jacob.e.keller@intel.com, jlelli@redhat.com, hch@infradead.org, bhelgaas@google.com, mike.marciniszyn@intel.com, dennis.dalessandro@intel.com, thomas.lendacky@amd.com, jiri@nvidia.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, lgoncalv@redhat.com, Thomas Gleixner Subject: Re: [PATCH v4 2/4] sched/isolation: Extend nohz_full to isolate managed IRQs Message-ID: <20201023132505.GZ2628@hirez.programming.kicks-ass.net> References: <20200928183529.471328-1-nitesh@redhat.com> <20200928183529.471328-3-nitesh@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200928183529.471328-3-nitesh@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Archived-At: List-Archive: List-Post: On Mon, Sep 28, 2020 at 02:35:27PM -0400, Nitesh Narayan Lal wrote: > Extend nohz_full feature set to include isolation from managed IRQS. This So you say it's for managed-irqs, the feature is actually called MANAGED_IRQ, but, AFAICT, it does *NOT* in fact affect managed IRQs. Also, as per Thomas' earlier points, managed-irqs are in fact perfectly fine and don't need help at at... > is required specifically for setups that only uses nohz_full and still > requires isolation for maintaining lower latency for the listed CPUs. > > Suggested-by: Frederic Weisbecker > Signed-off-by: Nitesh Narayan Lal > --- > kernel/sched/isolation.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c > index 5a6ea03f9882..9df9598a9e39 100644 > --- a/kernel/sched/isolation.c > +++ b/kernel/sched/isolation.c > @@ -141,7 +141,7 @@ static int __init housekeeping_nohz_full_setup(char *str) > unsigned int flags; > > flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | > - HK_FLAG_MISC | HK_FLAG_KTHREAD; > + HK_FLAG_MISC | HK_FLAG_KTHREAD | HK_FLAG_MANAGED_IRQ; > > return housekeeping_setup(str, flags); > } > -- > 2.18.2 >