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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 759F8ECDE5F for ; Thu, 19 Jul 2018 13:28:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B7B220684 for ; Thu, 19 Jul 2018 13:28:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B7B220684 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 S1731953AbeGSOLt (ORCPT ); Thu, 19 Jul 2018 10:11:49 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:43086 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731577AbeGSOLt (ORCPT ); Thu, 19 Jul 2018 10:11:49 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 58B617A7E5; Thu, 19 Jul 2018 13:28:38 +0000 (UTC) Received: from krava (ovpn-204-211.brq.redhat.com [10.40.204.211]) by smtp.corp.redhat.com (Postfix) with SMTP id 52D9D1C5B9; Thu, 19 Jul 2018 13:28:35 +0000 (UTC) Date: Thu, 19 Jul 2018 15:28:34 +0200 From: Jiri Olsa To: Cong Wang Cc: LKML , Peter Zijlstra , Ingo Molnar , Linus Torvalds , Arnaldo Carvalho de Melo , Alexander Shishkin , Namhyung Kim , stable Subject: Re: [PATCH] perf/core: fix a possible deadlock scenario Message-ID: <20180719132834.GF18667@krava> References: <20180716215101.4713-1-xiyou.wangcong@gmail.com> <20180718081905.GA13520@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.0 (2018-05-17) X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Thu, 19 Jul 2018 13:28:38 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Thu, 19 Jul 2018 13:28:38 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'jolsa@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 18, 2018 at 01:21:11PM -0700, Cong Wang wrote: SNIP > > hum, the swevent pmu does not triger NMI, so that timer > > will never be touched in NMI context > > Good to know! So I worry too much here. > > But still, given hrtimer interrupt is called with IRQ disabled, getting > stuck in a hrtimer callback could also block IPI handler, therefore > causing soft lockups. > > Let me know if you want me to adjust the changelog for this. yep, it's confusing, I think it should be removed from changelog jirka