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=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 A75EAC04AB3 for ; Mon, 13 May 2019 08:37:16 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 7D62A2086A for ; Mon, 13 May 2019 08:37:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="sj86Fxny" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7D62A2086A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=tsyRJuMoKMZHnqUhYtlKPv5uh4KeDl459tVRtCo96MU=; b=sj86FxnyI5KzNRhYa5TVaW7oN 9WAJEdxRt3LnPHXR6YQRQ5BbJ9vrGUlz1pW9Hn7A47DHXKBt7ZBYG4IQwep4+2w4zfQnrqIRgRkIg hjKP/8Wsi9FSokbbpz8sQYlb1phoMNcEHayW8KW8FvqgoCJi3zYzV7jzfZURNDPZXeYH/wF/HH1ar wW1kfP3I7OrT4U6bQfsn0N9/+7FIBCLJ68NdT/Qcya4yAEhxHXQGgSu35hXiVIjD6SVELFbL8ic0M KtdL+RP5frUI7C0sYqA7aOfXXDu+xu2LX/EkUyOJLdMs9DS80XitxEx/lh3DD92q2M50HJ5eg5hMl hZnYf9A1Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hQ6SN-0004le-2K; Mon, 13 May 2019 08:37:11 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hQ6SK-0004lC-8C for linux-arm-kernel@lists.infradead.org; Mon, 13 May 2019 08:37:09 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AC848341; Mon, 13 May 2019 01:37:05 -0700 (PDT) Received: from [10.1.196.93] (en101.cambridge.arm.com [10.1.196.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D6FB63F7B7; Mon, 13 May 2019 01:37:03 -0700 (PDT) Subject: Re: [PATCH 5/5] docs: coresight: Document snapshot mode To: leo.yan@linaro.org, mathieu.poirier@linaro.org References: <20190501175052.29667-1-mathieu.poirier@linaro.org> <20190501175052.29667-6-mathieu.poirier@linaro.org> <20190511073229.GA18064@leoy-ThinkPad-X240s> From: Suzuki K Poulose Message-ID: <77e437ed-99b2-670e-7e29-33be584f2bd0@arm.com> Date: Mon, 13 May 2019 09:37:01 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190511073229.GA18064@leoy-ThinkPad-X240s> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190513_013708_297394_CA8857AA X-CRM114-Status: GOOD ( 18.57 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: corbet@lwn.net, alexander.shishkin@linux.intel.com, coresight@lists.linaro.org, acme@kernel.org, peterz@infradead.org, mingo@redhat.com, Mike.leach@arm.com, linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, On 11/05/2019 08:32, Leo Yan wrote: > On Wed, May 01, 2019 at 11:50:52AM -0600, Mathieu Poirier wrote: > > [...] > >> +2.2) Snapshot mode: >> + >> +Using perf's built-in snapshot mode with CoreSight tracers is supported - to >> +do so the '-S' command line option needs to be specified. Since current sink >> +devices are used in double-buffer mode when operated from the perf interface, >> +the size of the perf ring buffer needs to be adjusted to match the size of the >> +buffer used by the CoreSight sinks. From the perf command line it is possible >> +to specify the number of pages to use for a session using the '-m,X' option, >> +where X is the amount of pages. >> + >> +The system memory buffer used by ETR devices is automatically adjusted >> +to match the size of the perf ring buffer and as such does not need to be >> +modified on the perf command line. For ETB and ETF devices the perf ring >> +buffer size need to be adjusted to match the size of the internal buffer. >> + >> +The following examples assume a system page size of 4096 byte: >> + >> + # cat /sys/bus/coresight/devices/20010000.etb/mgmt/rdp >> + 0x2000 >> + # perf record -e cs_etm/@20010000.etf/ -S -m,8 --per-thread $APP > > In this case it shows the usage for etb, thus should: > s/20010000.etf/20010000.etb/ > > BTW, the user needs to convert the rdp to byte size with multiplying 4, > it's good to explain for this in the doc or give related info in the > driver warning log. If at all we want to match the aux space size with that of the device buffer, I recommend exposing this via a new "buf_pages" attribute under the sysfs to help the user. Cheers Suzuki _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel