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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 F3F60C3815B for ; Wed, 15 Apr 2020 11:54:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C627F206A2 for ; Wed, 15 Apr 2020 11:54:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586951654; bh=QGF7u/cPWJ5PqpDZ6tAaNUUCujAeJ37DZ/ssCQQWpJg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tOlBX8Gl2cbo1qXCUnU0NQ/hANpQ5jjCyHNu6lq05bpkOOgxSPqJXSUeTcSdL822i YlbmFAW8szRp2eh7ALeCARvzQXacqSAjAvmeWrorFvsLgs8/DriC1jDsI0fFoWXekM PTZcdLLO32//eqkCokuwDPGDLKGBKtjzHAwd5IvI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2897856AbgDOLyM (ORCPT ); Wed, 15 Apr 2020 07:54:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:38200 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2409159AbgDOLpU (ORCPT ); Wed, 15 Apr 2020 07:45:20 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 221A12137B; Wed, 15 Apr 2020 11:45:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586951119; bh=QGF7u/cPWJ5PqpDZ6tAaNUUCujAeJ37DZ/ssCQQWpJg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1+XukrLuF765rL0RYQEBs4E330R1bB4qVpML/KUcklzRwCIDTj/HWyoIiyjqDaBYt pwvvGaJg4iKoCYlX4LIJCeT0KWqj3ZcXvbLEys4DPxB3eMo7C55kAJye9sqTaLrqFJ 5S33S7ADpkRpFfQDsEi/nPEdHZzwjs2rJF7vSeHE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Thomas Richter , Vasily Gorbik , Sasha Levin , linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 33/84] s390/cpum_sf: Fix wrong page count in error message Date: Wed, 15 Apr 2020 07:43:50 -0400 Message-Id: <20200415114442.14166-33-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200415114442.14166-1-sashal@kernel.org> References: <20200415114442.14166-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 fdb8083e7870c..229e1e2f8253a 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -1589,6 +1589,7 @@ 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