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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 B24D7C5DF62 for ; Wed, 6 Nov 2019 09:40:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 809D32087E for ; Wed, 6 Nov 2019 09:40:39 +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="i44IRP3w" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730955AbfKFJki (ORCPT ); Wed, 6 Nov 2019 04:40:38 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:46648 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725906AbfKFJkh (ORCPT ); Wed, 6 Nov 2019 04:40:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=/YQ9LfHefZM8w/IcM4p+bj0fVJMJxLHGZzxqfEZnLwE=; b=i44IRP3wDyAe84Z1rp5zkOS+4 /vJhxu4UO8U1F52m8AH0k6cV6GitjIwq0zuzMVt3GH+eGIEJTuFQi9uceN7tK7twwn+lPyRQ4ky6V eIHQNc5lyxzRca3fzXKwYzmuX0Iyzo2MC55iA/aUv1Tn6UZScvBSHf3oc+WxrtV1CwxH7nO//4v0r xA7/VSFbCMVIXpxqmE9hJzKR6L4aRa+GTwKumN1SIZbE3fC/LL/yvcFKfUeOKGmjx+RYfPQatNAjd dKwT0dfdrPM987KmXoIJdl+0qheY4CXPACSazbMHnYOB/eqAEuyK8Z3rZwf3vsoB+A7JSyuCgqY1B MgRcLmYrg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iSHnm-0004AE-KN; Wed, 06 Nov 2019 09:40:34 +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 280B4300692; Wed, 6 Nov 2019 10:39:28 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2881C29ABB5F9; Wed, 6 Nov 2019 10:40:32 +0100 (CET) Date: Wed, 6 Nov 2019 10:40:32 +0100 From: Peter Zijlstra To: Ganapatrao Prabhakerrao Kulkarni Cc: "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "mingo@redhat.com" , "will@kernel.org" , "mark.rutland@arm.com" , "corbet@lwn.net" , "gklkml16@gmail.com" Subject: Re: [PATCH 1/2] perf/core: Adding capability to disable PMUs event multiplexing Message-ID: <20191106094032.GV4131@hirez.programming.kicks-ass.net> References: <1573002091-9744-1-git-send-email-gkulkarni@marvell.com> <1573002091-9744-2-git-send-email-gkulkarni@marvell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1573002091-9744-2-git-send-email-gkulkarni@marvell.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, Nov 06, 2019 at 01:01:40AM +0000, Ganapatrao Prabhakerrao Kulkarni wrote: > When PMUs are registered, perf core enables event multiplexing > support by default. There is no provision for PMUs to disable > event multiplexing, if PMUs want to disable due to unavoidable > circumstances like hardware errata etc. > > Adding PMU capability flag PERF_PMU_CAP_NO_MUX_EVENTS and support > to allow PMUs to explicitly disable event multiplexing. This doesn't make sense, multiplexing relies on nothing that normal event scheduling doesn't also rely on. Either you can schedule different sets of events, or you cannot. NAK.