From patchwork Mon Apr 3 14:08:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 13198256 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 938A2C76196 for ; Mon, 3 Apr 2023 14:37:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233718AbjDCOhy (ORCPT ); Mon, 3 Apr 2023 10:37:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233689AbjDCOhu (ORCPT ); Mon, 3 Apr 2023 10:37:50 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9EF2635032; Mon, 3 Apr 2023 07:37:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 7F5D3B81CB5; Mon, 3 Apr 2023 14:37:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D59A1C433EF; Mon, 3 Apr 2023 14:37:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680532641; bh=UMk1yWcwvsggJJjnaJ9yTLb2WQw1KXCFuCFy3Q+rgHE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HepWkbxpu2tCemP1r99PRIjNkH5QLOTAcs6xZl3EVfVOLjE0iS53T6XfGvAB38lgk un7JPD72Vyh7PBWjnNbxwf5MFACGIyUe0CUzQ6Ze8HAkPL7N8VZutIUgAi4jS4gBvW uAiYQJff8KlDm1SaGgsoQa7/uiPtjRb26Pfw/IP8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Prarit Bhargava , linux-pm@vger.kernel.org, Len Brown , Sasha Levin Subject: [PATCH 6.1 061/181] tools/power turbostat: Fix /dev/cpu_dma_latency warnings Date: Mon, 3 Apr 2023 16:08:16 +0200 Message-Id: <20230403140417.120319370@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230403140415.090615502@linuxfoundation.org> References: <20230403140415.090615502@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Prarit Bhargava [ Upstream commit 40aafc7d58d3544f152a863a0e9863014b6d5d8c ] When running as non-root the following error is seen in turbostat: turbostat: fopen /dev/cpu_dma_latency : Permission denied turbostat and the man page have information on how to avoid other permission errors, so these can be fixed the same way. Provide better /dev/cpu_dma_latency warnings that provide instructions on how to avoid the error, and update the man page. Signed-off-by: Prarit Bhargava Cc: linux-pm@vger.kernel.org Signed-off-by: Len Brown Signed-off-by: Sasha Levin --- tools/power/x86/turbostat/turbostat.8 | 2 ++ tools/power/x86/turbostat/turbostat.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/power/x86/turbostat/turbostat.8 b/tools/power/x86/turbostat/turbostat.8 index c7b26a3603afe..3e1a4c4be001a 100644 --- a/tools/power/x86/turbostat/turbostat.8 +++ b/tools/power/x86/turbostat/turbostat.8 @@ -344,6 +344,8 @@ Alternatively, non-root users can be enabled to run turbostat this way: # chmod +r /dev/cpu/*/msr +# chmod +r /dev/cpu_dma_latency + .B "turbostat " reads hardware counters, but doesn't write them. So it will not interfere with the OS or other programs, including diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c index aba460410dbd1..c24054e3ef7ad 100644 --- a/tools/power/x86/turbostat/turbostat.c +++ b/tools/power/x86/turbostat/turbostat.c @@ -5482,7 +5482,7 @@ void print_dev_latency(void) retval = read(fd, (void *)&value, sizeof(int)); if (retval != sizeof(int)) { - warn("read %s\n", path); + warn("read failed %s\n", path); close(fd); return; }