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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,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 61328C433E0 for ; Tue, 16 Feb 2021 12:07:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 10A8364DDA for ; Tue, 16 Feb 2021 12:07:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230383AbhBPMHQ (ORCPT ); Tue, 16 Feb 2021 07:07:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49092 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230336AbhBPMFQ (ORCPT ); Tue, 16 Feb 2021 07:05:16 -0500 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B530FC061574 for ; Tue, 16 Feb 2021 04:04:35 -0800 (PST) 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=6SOYiIoOIrJswiH+kvkOeoh2i6yuirVJqSRi5GsGhK0=; b=e6iu4OknmrFp2oKWbuaRUYmCIN p/ZrAWYsqdKtH7nm3/xoQlwNTL6TsdK5U5aMda2JDUp0WSE6CYxHcO1aZCVqZcLnNoSXdcM27z8ow xJpnFe5Hqe5pyJs9nW2rixRyAhK8BCnzZptCX/u5mrCtXWCYIVizJRcRmPj0HGC5PC0jws2c25YhZ MaVgRMso4MvKueqFLR8qbgxSg+el0xbb3N8vWW3ZNKSCBAZEnTLuCzKTDIpA+or55BEr5VNOZb0vC eOiys62qNmda6jDk8OkWpW0zFzCtTttbErldPxT1PwdOIzwZ5aLXgEDFwk6PzbLBegQf1MViqI0pd 4P3DHhGw==; 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 1lBz5Z-0000fc-Pv; Tue, 16 Feb 2021 12:04:21 +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 D69923011E6; Tue, 16 Feb 2021 13:04:18 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id ADE8220577E14; Tue, 16 Feb 2021 13:04:18 +0100 (CET) Date: Tue, 16 Feb 2021 13:04:18 +0100 From: Peter Zijlstra To: Nadav Amit Cc: Thomas Gleixner , linux-kernel@vger.kernel.org, Andy Lutomirski , Dave Hansen , Nadav Amit , Rik van Riel , Josh Poimboeuf Subject: Re: [PATCH v5 1/8] smp: Run functions concurrently in smp_call_function_many_cond() Message-ID: References: <20210209221653.614098-1-namit@vmware.com> <20210209221653.614098-2-namit@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210209221653.614098-2-namit@vmware.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 09, 2021 at 02:16:46PM -0800, Nadav Amit wrote: > @@ -894,17 +911,12 @@ EXPORT_SYMBOL(on_each_cpu_mask); > void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func, > void *info, bool wait, const struct cpumask *mask) > { > - int cpu = get_cpu(); > + unsigned int scf_flags = SCF_RUN_LOCAL; > > - smp_call_function_many_cond(mask, func, info, wait, cond_func); > - if (cpumask_test_cpu(cpu, mask) && cond_func(cpu, info)) { > - unsigned long flags; > + if (wait) > + scf_flags |= SCF_WAIT; > > - local_irq_save(flags); > - func(info); > - local_irq_restore(flags); > - } > - put_cpu(); > + smp_call_function_many_cond(mask, func, info, scf_flags, cond_func); > } > EXPORT_SYMBOL(on_each_cpu_cond_mask); You lost the preempt_disable() there, I've added it back: --- --- a/kernel/smp.c +++ b/kernel/smp.c @@ -920,7 +920,9 @@ void on_each_cpu_cond_mask(smp_cond_func if (wait) scf_flags |= SCF_WAIT; + preempt_disable(); smp_call_function_many_cond(mask, func, info, scf_flags, cond_func); + preempt_enable(); } EXPORT_SYMBOL(on_each_cpu_cond_mask);