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=-5.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 66219C282DD for ; Mon, 8 Apr 2019 08:22:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 36D8B20870 for ; Mon, 8 Apr 2019 08:22:41 +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="JGrbyuYL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726539AbfDHIWk (ORCPT ); Mon, 8 Apr 2019 04:22:40 -0400 Received: from merlin.infradead.org ([205.233.59.134]:54272 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726005AbfDHIWj (ORCPT ); Mon, 8 Apr 2019 04:22:39 -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=QYFM2r8ApWnkhG6CF3UeQCeWjU2P81rZ50Qu9OE9ZdU=; b=JGrbyuYLQAOxaWLmBuKm8uAur Hxo1/clWd3mc/eAAVxx9AUpWOeK4SPZGvww4TgNt5Tr0EUc+6jQAQ35Bdd5YZPNOrfWJzssGObx5i aQX1g0eCiwpfEFztIIefiweAR2AyHBMBiOjMh7lTM2rxGjzU9oZY0hUJewpsrxSn2U+oClfkWHv/f apBaNRo/GaxxocYjgJUtfyU+/WR2/4huwQV1D/9mlEU5PsrvscVItz6SRwjJlTYGfqg39FWkW4jOC 1xoBBZ0TLLQNXBEW8Be4k0R/F6cF58z7M3sKwyXthwFjsyVpZHrkVuuHh51KhqaKYl9vlZdlsCcl7 1CqXx4Prg==; 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 1hDPXz-0005MX-R8; Mon, 08 Apr 2019 08:22:32 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 1CD302038C24B; Mon, 8 Apr 2019 10:22:29 +0200 (CEST) Date: Mon, 8 Apr 2019 10:22:29 +0200 From: Peter Zijlstra To: Thomas-Mich Richter Cc: Kees Cook , acme@redhat.com, Linux Kernel Mailing List , Heiko Carstens , Hendrik Brueckner , Martin Schwidefsky Subject: Re: WARN_ON_ONCE() hit at kernel/events/core.c:330 Message-ID: <20190408082229.GI4038@hirez.programming.kicks-ass.net> References: <20190403104103.GE4038@hirez.programming.kicks-ass.net> <20190404110909.GY4038@hirez.programming.kicks-ass.net> <20190404130300.GF14281@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Mon, Apr 08, 2019 at 09:12:28AM +0200, Thomas-Mich Richter wrote: > > Does the below cure things? It's not exactly pretty, but it could just > > do the trick. > > > > --- > > diff --git a/kernel/events/core.c b/kernel/events/core.c > > index dfc4bab0b02b..d496e6911442 100644 > > --- a/kernel/events/core.c > > +++ b/kernel/events/core.c > > @@ -2009,8 +2009,8 @@ event_sched_out(struct perf_event *event, > > event->pmu->del(event, 0); > > event->oncpu = -1; > > > > - if (event->pending_disable) { > > - event->pending_disable = 0; > > + if (event->pending_disable == smp_processor_id()) { > > + event->pending_disable = -1; > > state = PERF_EVENT_STATE_OFF; > > } > > perf_event_set_state(event, state); > > @@ -2198,7 +2198,7 @@ EXPORT_SYMBOL_GPL(perf_event_disable); > > > > void perf_event_disable_inatomic(struct perf_event *event) > > { > > - event->pending_disable = 1; > > + event->pending_disable = smp_processor_id(); > > irq_work_queue(&event->pending); > > } > > > > @@ -5822,8 +5822,8 @@ static void perf_pending_event(struct irq_work *entry) > > * and we won't recurse 'further'. > > */ > > > > - if (event->pending_disable) { > > - event->pending_disable = 0; > > + if (event->pending_disable == smp_processor_id()) { > > + event->pending_disable = -1; > > perf_event_disable_local(event); > > } > > > > @@ -10236,6 +10236,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, > > > > > > init_waitqueue_head(&event->waitq); > > + event->pending_disable = -1; > > init_irq_work(&event->pending, perf_pending_event); > > > > mutex_init(&event->mmap_mutex); > > > > Peter, > > very good news, your fix ran over the weekend without any hit!!! > > Thanks very much for your help. Do you submit this patch to the kernel mailing list? Most excellent, let me go write a Changelog. Could I convince you to implement arch_irq_work_raise() for s390?