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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 EE215C433E0 for ; Thu, 28 May 2020 12:28:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA780214F1 for ; Thu, 28 May 2020 12:28:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590668931; bh=YJHXDrxBQ7egNlQcu8sdaybqWoRD4SjKVsfa1BopeZg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=kN7Ak0ApMop7czZxQdSZfRnSUehAHuU+dC2y5XIV6cOOgtf4GJ8HcO1Enr2qDrtuv KNAyFY8hXtOX2Dea9lVevkFogRde0p+rlPiqiWXMAW5k2Nz2zs4JOIlJD3UPUGSrCO 3oh2kKgkT9mLqe3q91jHvnKH6IDHaSXLDo05d4l0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389750AbgE1M2v (ORCPT ); Thu, 28 May 2020 08:28:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:41730 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389675AbgE1M2t (ORCPT ); Thu, 28 May 2020 08:28:49 -0400 Received: from localhost (lfbn-ncy-1-324-171.w83-196.abo.wanadoo.fr [83.196.159.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8384C20888; Thu, 28 May 2020 12:28:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590668929; bh=YJHXDrxBQ7egNlQcu8sdaybqWoRD4SjKVsfa1BopeZg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=xeZ7RBcI5V4Si3IJWFfn09Fb2S58vTt2pusnlRlUfra1SoW88gur2womTM6TIPah+ YTlBo2UZD8sDGfImspOamNNS7OQjNOdwgjf2Z/4XFdjhH5ticLexjRf3QHZsKmDz61 XfaE2WrKtm1NV3df9pTneOTFVogiLvhBTAu49qFw= Date: Thu, 28 May 2020 14:28:46 +0200 From: Frederic Weisbecker To: Peter Zijlstra Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, x86@kernel.org, cai@lca.pw, mgorman@techsingularity.net Subject: Re: [RFC][PATCH 2/7] smp: Optimize flush_smp_call_function_queue() Message-ID: <20200528122845.GA551@lenoir> References: <20200526161057.531933155@infradead.org> <20200526161907.836818381@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200526161907.836818381@infradead.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 26, 2020 at 06:10:59PM +0200, Peter Zijlstra wrote: > The call_single_queue can contain (two) different callbacks, > synchronous and asynchronous. The current interrupt handler runs them > in-order, which means that remote CPUs that are waiting for their > synchronous call can be delayed by running asynchronous callbacks. > > Rework the interrupt handler to first run the synchonous callbacks. > > Signed-off-by: Peter Zijlstra (Intel) I hope we are not unlucky enough to have dependencies between some async and sync callbacks that require the whole execution in order. Reviewed-by: Frederic Weisbecker (Sweet llist dance, I think I need fresh air and coffee now).