From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 91B08173; Tue, 30 Sep 2025 15:20:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759245625; cv=none; b=LfO6qclTzixVT/VdI1NjBY66xeKeRHAoYD6ye7LMCo9NyV+YIwkwFyEiicSw8Rzc6qeW1PXrNtmKItifV+TVd98jJbMIEgiBC0aTWPStll/1SHj6Oz/Qo/7M1ea2v98qs5xFrKAwONuWU1pl/MyJpDBYWJlBfDmeoJ2NBO2rXGE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759245625; c=relaxed/simple; bh=4e30QlnkrFHP1IK4ssY3GXRdwGRiC58ydkd81fVN7Ac=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rnX8oseEwfsqj+SiF7qltMyW/rBnpDxpkj8cao2jP9zYOnHVJmKTtU+SG9GNz2YAIO3cMbyvGD7l9w9C5aneR99HfTdpJJ+5BOr+V8shZ2VeiI+RdQeKHVq04pgWuFmTZEW57mXWrThOLaT6xiqx66mXOoJliQJ6nfroL6G92qE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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> 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