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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 739DBC433E7 for ; Tue, 1 Sep 2020 16:54:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E760207D3 for ; Tue, 1 Sep 2020 16:54:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598979283; bh=oSERYQXpQfBuJnrHVHRieZoE8sDcxceBGWQ9X7mqF34=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=K3uty1z4v+Mxcb4L6bXavawAr5I+h/OQUo6QArnPqaOh/jtSmQDbjHKjzFEQyygJC MprmZaY7EU65grsxIBxOQXsfZ5Bm9d7WdEi5ON6+nuNPO1yMph7ipn+wW+w0MJfJIA UaRxEVJeNZwpfuUqj1dnRAkcOxwR/Cvl1NTEGrjo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729666AbgIAQyk (ORCPT ); Tue, 1 Sep 2020 12:54:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:48396 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729957AbgIAPY1 (ORCPT ); Tue, 1 Sep 2020 11:24:27 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3863D21534; Tue, 1 Sep 2020 15:24:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598973866; bh=oSERYQXpQfBuJnrHVHRieZoE8sDcxceBGWQ9X7mqF34=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2AmVj6+07AgY6iwEfY2v9qZvZw1L/AdIZl5hXE+T3nPh73b2jiQn6cP3aDEnSBCF/ 0JpUFQ2279yEcTXLJDF4rWW6PFoH4PglKOfrBSqsjAzGoUB3ilE3Lq14f1PE9NCEHq DsYdp2DAkYev1dtVHXiQGfT9sz14jRdBFC4ZrIYQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexey Kardashevskiy , Athira Rajeev , Michael Ellerman , Sasha Levin Subject: [PATCH 4.19 079/125] powerpc/perf: Fix soft lockups due to missed interrupt accounting Date: Tue, 1 Sep 2020 17:10:34 +0200 Message-Id: <20200901150938.445456964@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200901150934.576210879@linuxfoundation.org> References: <20200901150934.576210879@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Athira Rajeev [ Upstream commit 17899eaf88d689529b866371344c8f269ba79b5f ] Performance monitor interrupt handler checks if any counter has overflown and calls record_and_restart() in core-book3s which invokes perf_event_overflow() to record the sample information. Apart from creating sample, perf_event_overflow() also does the interrupt and period checks via perf_event_account_interrupt(). Currently we record information only if the SIAR (Sampled Instruction Address Register) valid bit is set (using siar_valid() check) and hence the interrupt check. But it is possible that we do sampling for some events that are not generating valid SIAR, and hence there is no chance to disable the event if interrupts are more than max_samples_per_tick. This leads to soft lockup. Fix this by adding perf_event_account_interrupt() in the invalid SIAR code path for a sampling event. ie if SIAR is invalid, just do interrupt check and don't record the sample information. Reported-by: Alexey Kardashevskiy Signed-off-by: Athira Rajeev Tested-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1596717992-7321-1-git-send-email-atrajeev@linux.vnet.ibm.com Signed-off-by: Sasha Levin --- arch/powerpc/perf/core-book3s.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 4004dbdab9c7b..d407b73298171 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -2087,6 +2087,10 @@ static void record_and_restart(struct perf_event *event, unsigned long val, if (perf_event_overflow(event, &data, regs)) power_pmu_stop(event, 0); + } else if (period) { + /* Account for interrupt in case of invalid SIAR */ + if (perf_event_account_interrupt(event)) + power_pmu_stop(event, 0); } } -- 2.25.1