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=-5.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,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 8B728C2D0CE for ; Fri, 24 Jan 2020 09:16:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 507902071A for ; Fri, 24 Jan 2020 09:16:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ktJyqCX5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730103AbgAXJQJ (ORCPT ); Fri, 24 Jan 2020 04:16:09 -0500 Received: from merlin.infradead.org ([205.233.59.134]:39998 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729384AbgAXJQJ (ORCPT ); Fri, 24 Jan 2020 04:16:09 -0500 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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=hmixrUXurqOegKNhzF9h4CdZ3dMfH0LOWEyJXzMjgjo=; b=ktJyqCX5GLB6FKAUL/9nirdsj qztnJToZqMYplKB5b94b5BVmWplOxoxCW39NC8wNC+MeS6bmkzzQWQQ0RQZ5OTQcRxEHx1y0YZ4na tgk5wsycMLzp0OwcB/JKd8vWOA62Axk2UBwOQZJk+hzyq/NsP65vYQFQWmcnvfjvzCrAl+iILNJ/F ZJwzD3wf0/sc1SzRm0kgCgJFbKQC3iM8eKyN5CweoKY0eBQ20rczMvDoiGqjnoqvxj+Z12OcRWuzY WGpr1iE2Ne45kfRE7FAkfq1R8ZE7OtXxHT/VcYWcxnwTmxHNz6Vl1iz6HcCfUoUcm7LKIbPQx02eu s1EqYTmOw==; 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 1iuv4G-0002ZI-Ah; Fri, 24 Jan 2020 09:15:56 +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 63336300677; Fri, 24 Jan 2020 10:14:12 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id D5C7B2B715B6B; Fri, 24 Jan 2020 10:15:52 +0100 (CET) Date: Fri, 24 Jan 2020 10:15:52 +0100 From: Peter Zijlstra To: Song Liu Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, Andi Kleen , Alexander Shishkin , Arnaldo Carvalho de Melo , Jiri Olsa , Namhyung Kim , Thomas Gleixner Subject: Re: [PATCH v2] perf/core: install cgroup events to correct cpuctx Message-ID: <20200124091552.GB14914@hirez.programming.kicks-ass.net> References: <20200122195027.2112449-1-songliubraving@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200122195027.2112449-1-songliubraving@fb.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 22, 2020 at 11:50:27AM -0800, Song Liu wrote: > cgroup events are always installed in the cpuctx. However, when it is not > installed via IPI, list_update_cgroup_event() adds it to cpuctx of current > CPU, which triggers the following with CONFIG_DEBUG_LIST: > > [ 31.777570] list_add double add: new=ffff888ff7cf0db0, prev=ffff888ff7ce82f0, next=ffff888ff7cf0db0. > To reproduce this, we can simply run: > perf stat -e cs -a & > perf stat -e cs -G anycgroup > > Fix this by installing it to cpuctx that contains event->ctx, and the > proper cgrp_cpuctx_list. > > Fixes: db0503e4f675 ("perf/core: Optimize perf_install_in_event()") > Suggested-by: Peter Zijlstra (Intel) > Cc: Andi Kleen > Cc: Peter Zijlstra (Intel) > Cc: Alexander Shishkin > Cc: Arnaldo Carvalho de Melo > Cc: Jiri Olsa > Cc: Namhyung Kim > Cc: Thomas Gleixner > Signed-off-by: Song Liu Thanks!