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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7D55BCCA468 for ; Tue, 30 Sep 2025 15:20:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=1aXr7PIDJqhppMsCfIRxXVKxK+DvbbfF1pf2Cjk0GWQ=; b=cxhnKWWZ21wFT4zY/UK5cpM6XR rwL6CnnAILaqdh5CzgT1pe3xYIyxORHfbqT+8mXISz+c049icTyG3FB1zsynPu+FGBUZhz74oA6E6 mou5TJIkYNo0bJK6Mmw3IbAk1V3d7QBGRnjMkFlLOCCeScnqF9Hfiddxw2ImSEiygwkA0gHAg1BSp cWGJ/woW6SoDEU86T6VkDNeALTSYrwLF4c+RrL8+yuM6kg1+NF07ua9F2ZjgBM3/n8DEqgh+5uLtY oLReDrGICPpK/qDG5VNmiP/jR9CzUQhmjSM7MBQtCM9oQ89aI/ghrVl+siL9By41WPFjm+yVueutc iwg5VxNQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v3c9S-00000005dka-1COY; Tue, 30 Sep 2025 15:20:26 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v3c9P-00000005dkB-2hqA for linux-arm-kernel@lists.infradead.org; Tue, 30 Sep 2025 15:20:24 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A97D81424; Tue, 30 Sep 2025 08:20:14 -0700 (PDT) Received: from localhost (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 59BD13F59E; Tue, 30 Sep 2025 08:20:22 -0700 (PDT) Date: Tue, 30 Sep 2025 16:20:20 +0100 From: Leo Yan To: James Clark Cc: Suzuki K Poulose , Mike Leach , Alexander Shishkin , Jonathan Corbet , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v2 0/6] coresight: Add format attribute for setting the timestamp interval Message-ID: <20250930152020.GL7985@e132581.arm.com> References: <20250814-james-cs-syncfreq-v2-0-c76fcb87696d@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250814-james-cs-syncfreq-v2-0-c76fcb87696d@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250930_082023_722427_60225B54 X-CRM114-Status: GOOD ( 10.44 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Aug 14, 2025 at 11:49:51AM +0100, James Clark wrote: [...] > This is added as an event format attribute, rather than a Coresight > config because it's something that the driver is already configuring > automatically in Perf mode with any unused counter, so it's not possible > to modify this with a config. Tested on Juno-r2 for this series: # /mnt/build/perf record -e cs_etm/timestamp=1,ts_level=15/ -- ls # /mnt/build/perf script -D | grep I_TIMESTAMP | wc 1305 11745 83337 # /mnt/build/perf record -e cs_etm/timestamp=1,ts_level=0/ -- ls # /mnt/build/perf script -D | grep I_TIMESTAMP | wc 120668 1086012 7705024 We can see a small counter (2 ^ 0 = 1) that records significant timestamp packets. Tested-by: Leo Yan