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=-0.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,T_DKIM_INVALID autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 9379DC433EF for ; Tue, 12 Jun 2018 20:11:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4766520891 for ; Tue, 12 Jun 2018 20:11:46 +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="kbQFDk2y" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4766520891 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934039AbeFLULo (ORCPT ); Tue, 12 Jun 2018 16:11:44 -0400 Received: from merlin.infradead.org ([205.233.59.134]:57862 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932768AbeFLULn (ORCPT ); Tue, 12 Jun 2018 16:11:43 -0400 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=6Iu/EpOVdAzvxBQSPO9hjvb9m3X5e0VC+6eHFalIkes=; b=kbQFDk2y3lay1p2O9VqjdLwMr JpJJ/9FkzWmgAGh9QSM0guUHpEU3JLaZSlHP8UHYzlZkRmWcJ1xjrg10D5TVjbpR23NF0pDQRmzv0 k24WRrL6xTGQg/K7K9Nt/gd7CpfY9TtLD6yNyFDhA1HKIQ2TuyfZsBeqnwGpykbzIUFD9ed//E5fs 6nyEhCd54rFewY9lM7AWM4mXXvtMXmBee1/sza5QB/IkfQEpeonnbLCWcTC9EBUcv3B7N7oiHpnet K08V4C3A8oTyKEsHp8dSukghV3yhYk+tbSu+3zOKECosndW5eoIVeS0gXfZP3OcVpzzFO/u8RyMrS kVRXdKEow==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fSpda-0006PP-Bv; Tue, 12 Jun 2018 20:11:30 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 7C439201EA7A3; Tue, 12 Jun 2018 22:11:27 +0200 (CEST) Date: Tue, 12 Jun 2018 22:11:27 +0200 From: Peter Zijlstra To: Alexander Shishkin Cc: Ingo Molnar , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, jolsa@redhat.com Subject: Re: [PATCH v1 1/6] perf: Disable PMU around address filter adjustment Message-ID: <20180612201127.GW12217@hirez.programming.kicks-ass.net> References: <20180612075117.65420-1-alexander.shishkin@linux.intel.com> <20180612075117.65420-2-alexander.shishkin@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180612075117.65420-2-alexander.shishkin@linux.intel.com> User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 12, 2018 at 10:51:12AM +0300, Alexander Shishkin wrote: > If the PMU is used for AUX data sampling, the hardware event that triggers > it may come in during a critical section of address filters adjustment (if > it's delivered as NMI) and in turn call the address filter sync code, > causing a spinlock recursion. Can you detail that a little more? How can sampling _ever_ get down that path?