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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 9FE50C5518A for ; Wed, 22 Apr 2020 10:14:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 791B42070B for ; Wed, 22 Apr 2020 10:14:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587550494; bh=VKvRnzrhE79l30fPjNatQ8L377zR5ldGkynql46Qu7k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=X4JhhEhqgZOEw3ocntr72RKYtIYSLYQvA4cl+844g5iV9Z2OwA03j4eprL5y93OQr RGI/Uz+Erca0GXXmtr/fTgcd8E9p/VsdxPQc7Di+TrVFKweewn/qNRLSPspUNfv3df uh2DpU/P3vEqZaKdRLFkSyQD0098uYTR7Y+sXhvs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729598AbgDVKOx (ORCPT ); Wed, 22 Apr 2020 06:14:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:49540 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729577AbgDVKOp (ORCPT ); Wed, 22 Apr 2020 06:14:45 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 5DEB920776; Wed, 22 Apr 2020 10:14:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587550484; bh=VKvRnzrhE79l30fPjNatQ8L377zR5ldGkynql46Qu7k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LTkvZ0poKx9A2RHXaqXaEdCUYyyq1leyuUB5d20lsxg6JbUJKSroXKxopXvHr45gM vTyKd8yAEREipUKpUZ+RR92FAYiwHX+GSuQrMlkMQ7Tv/D6O/YLslSUWLZFnC7x+jX kq/6gX3pQ26pK4Uha4B3dHhQAW+o8wQMyw4+lwG0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Richter , Vasily Gorbik , Sasha Levin Subject: [PATCH 4.19 35/64] s390/cpum_sf: Fix wrong page count in error message Date: Wed, 22 Apr 2020 11:57:19 +0200 Message-Id: <20200422095019.152022733@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095008.799686511@linuxfoundation.org> References: <20200422095008.799686511@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: Thomas Richter [ Upstream commit 4141b6a5e9f171325effc36a22eb92bf961e7a5c ] When perf record -e SF_CYCLES_BASIC_DIAG runs with very high frequency, the samples arrive faster than the perf process can save them to file. Eventually, for longer running processes, this leads to the siutation where the trace buffers allocated by perf slowly fills up. At one point the auxiliary trace buffer is full and the CPU Measurement sampling facility is turned off. Furthermore a warning is printed to the kernel log buffer: cpum_sf: The AUX buffer with 0 pages for the diagnostic-sampling mode is full The number of allocated pages for the auxiliary trace buffer is shown as zero pages. That is wrong. Fix this by saving the number of allocated pages before entering the work loop in the interrupt handler. When the interrupt handler processes the samples, it may detect the buffer full condition and stop sampling, reducing the buffer size to zero. Print the correct value in the error message: cpum_sf: The AUX buffer with 256 pages for the diagnostic-sampling mode is full Signed-off-by: Thomas Richter Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin --- arch/s390/kernel/perf_cpum_sf.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index 5bfb1ce129f4b..74a296cea21cc 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -1537,6 +1537,7 @@ static void hw_collect_aux(struct cpu_hw_sf *cpuhw) perf_aux_output_end(handle, size); num_sdb = aux->sfb.num_sdb; + num_sdb = aux->sfb.num_sdb; while (!done) { /* Get an output handle */ aux = perf_aux_output_begin(handle, cpuhw->event); -- 2.20.1