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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 A3604C433DB for ; Sat, 20 Feb 2021 12:13:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7354764EDE for ; Sat, 20 Feb 2021 12:13:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229732AbhBTMNI (ORCPT ); Sat, 20 Feb 2021 07:13:08 -0500 Received: from mail.xenproject.org ([104.130.215.37]:54760 "EHLO mail.xenproject.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbhBTMNF (ORCPT ); Sat, 20 Feb 2021 07:13:05 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject; bh=bQI3Ccup6yTIKmHa56nvcajDRXzkAB6HThNzesI2iXU=; b=lB2ygTAnJokH5Xh2dCOi/z2iZo gJEn36BjiNPpV/WPhRsJ1hbLzvpOxpIgdFONvx94OiQG5YIh8DqilRSb/6q3f2OzzHcyOycYs8AXm W6OQIhbdXauznCSyDbuErPjDa6qK7iSxYdS3yTFhyu9OSKi3zQFE85Qc9FEG5lvUmFWw=; Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lDR7Q-0002Ad-Ue; Sat, 20 Feb 2021 12:12:16 +0000 Received: from [54.239.6.185] (helo=a483e7b01a66.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1lDR7Q-0008An-I2; Sat, 20 Feb 2021 12:12:16 +0000 Subject: Re: [PATCH v3 3/8] xen/events: avoid handling the same event on two cpus at the same time To: Juergen Gross , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: Boris Ostrovsky , Stefano Stabellini , stable@vger.kernel.org References: <20210219154030.10892-1-jgross@suse.com> <20210219154030.10892-4-jgross@suse.com> From: Julien Grall Message-ID: <495a12e4-d54b-0841-07b2-5b0a0cea5d10@xen.org> Date: Sat, 20 Feb 2021 12:12:14 +0000 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <20210219154030.10892-4-jgross@suse.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Juergen, On 19/02/2021 15:40, Juergen Gross wrote: > When changing the cpu affinity of an event it can happen today that > (with some unlucky timing) the same event will be handled on the old > and the new cpu at the same time. > > Avoid that by adding an "event active" flag to the per-event data and > call the handler only if this flag isn't set. > > Cc: stable@vger.kernel.org > Reported-by: Julien Grall > Signed-off-by: Juergen Gross Reviewed-by: Julien Grall Cheers, -- Julien Grall