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=-3.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 5FBB4C433B4 for ; Sat, 17 Apr 2021 13:56:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3570061001 for ; Sat, 17 Apr 2021 13:56:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236485AbhDQN5K (ORCPT ); Sat, 17 Apr 2021 09:57:10 -0400 Received: from mga01.intel.com ([192.55.52.88]:60140 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236058AbhDQN5J (ORCPT ); Sat, 17 Apr 2021 09:57:09 -0400 IronPort-SDR: Sf+tmaw5V7DoCpgOMcizwHoNE5wX8dGGY4jB1iDV8lq8oeL4FhMZlivjo/vXiaMSZiFKMPpQWi xQwzZ9CTYruQ== X-IronPort-AV: E=McAfee;i="6200,9189,9957"; a="215722368" X-IronPort-AV: E=Sophos;i="5.82,229,1613462400"; d="scan'208";a="215722368" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Apr 2021 06:56:42 -0700 IronPort-SDR: rfkFROCfAr3fKHP9T+JiF0ymqW11+G9xkVZnj656scJEKzwTA3YPKDnlUNGFmaJQc98VE/wGfM 9iYrN9q4Enhg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,229,1613462400"; d="scan'208";a="419459743" Received: from um.fi.intel.com (HELO um) ([10.237.72.62]) by fmsmga008.fm.intel.com with ESMTP; 17 Apr 2021 06:56:36 -0700 From: Alexander Shishkin To: Yicong Yang , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, coresight@lists.linaro.org, linux-pci@vger.kernel.org Cc: helgaas@kernel.org, gregkh@linuxfoundation.org, lorenzo.pieralisi@arm.com, will@kernel.org, mark.rutland@arm.com, mathieu.poirier@linaro.org, suzuki.poulose@arm.com, mike.leach@linaro.org, leo.yan@linaro.org, jonathan.cameron@huawei.com, song.bao.hua@hisilicon.com, john.garry@huawei.com, prime.zeng@huawei.com, liuqi115@huawei.com, zhangshaokun@hisilicon.com, yangyicong@hisilicon.com, linuxarm@huawei.com, alexander.shishkin@linux.intel.com Subject: Re: [PATCH RESEND 0/4] Add support for HiSilicon PCIe Tune and Trace device In-Reply-To: <1618654631-42454-1-git-send-email-yangyicong@hisilicon.com> References: <1618654631-42454-1-git-send-email-yangyicong@hisilicon.com> Date: Sat, 17 Apr 2021 16:56:35 +0300 Message-ID: <8735vpf20c.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Yicong Yang writes: > The reason for not using perf is because there is no current support > for uncore tracing in the perf facilities. Not unless you count $ perf list|grep -ic uncore 77 > We have our own format > of data and don't need perf doing the parsing. Perf has AUX buffers, which are used for all kinds of own formats. > A similar approach for implementing this function is ETM, which use > sysfs for configuring and a character device for dumping data. And also perf. One reason ETM has a sysfs interface is because the driver predates perf's AUX buffers. Can't say if it's the only reason. I'm assuming you're talking about Coresight ETM. > Greg has some comments on our implementation and doesn't advocate > to build driver on debugfs [1]. So I resend this series to > collect more feedbacks on the implementation of this driver. > > Hi perf and ETM related experts, is it suggested to adapt this driver > to perf? Or is the debugfs approach acceptable? Otherwise use Aside from the above, I don't think the use of debugfs for kernel ABIs is ever encouraged. Regards, -- Ale 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=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 2C74DC433B4 for ; Sat, 17 Apr 2021 13:59:11 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 DD7DC611ED for ; Sat, 17 Apr 2021 13:59:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DD7DC611ED Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; 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Sat, 17 Apr 2021 13:56:52 +0000 IronPort-SDR: NKB4N4DviR9BCECq97KLpmaFjLMhQDzsCeURFdivpIkNQmkqtOlO5xOHyOLPTHNMSsrUiG/UKY eYMNZ+wCK0AA== X-IronPort-AV: E=McAfee;i="6200,9189,9957"; a="256477560" X-IronPort-AV: E=Sophos;i="5.82,229,1613462400"; d="scan'208";a="256477560" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Apr 2021 06:56:42 -0700 IronPort-SDR: rfkFROCfAr3fKHP9T+JiF0ymqW11+G9xkVZnj656scJEKzwTA3YPKDnlUNGFmaJQc98VE/wGfM 9iYrN9q4Enhg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,229,1613462400"; d="scan'208";a="419459743" Received: from um.fi.intel.com (HELO um) ([10.237.72.62]) by fmsmga008.fm.intel.com with ESMTP; 17 Apr 2021 06:56:36 -0700 From: Alexander Shishkin To: Yicong Yang , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, coresight@lists.linaro.org, linux-pci@vger.kernel.org Cc: helgaas@kernel.org, gregkh@linuxfoundation.org, lorenzo.pieralisi@arm.com, will@kernel.org, mark.rutland@arm.com, mathieu.poirier@linaro.org, suzuki.poulose@arm.com, mike.leach@linaro.org, leo.yan@linaro.org, jonathan.cameron@huawei.com, song.bao.hua@hisilicon.com, john.garry@huawei.com, prime.zeng@huawei.com, liuqi115@huawei.com, zhangshaokun@hisilicon.com, yangyicong@hisilicon.com, linuxarm@huawei.com, alexander.shishkin@linux.intel.com Subject: Re: [PATCH RESEND 0/4] Add support for HiSilicon PCIe Tune and Trace device In-Reply-To: <1618654631-42454-1-git-send-email-yangyicong@hisilicon.com> References: <1618654631-42454-1-git-send-email-yangyicong@hisilicon.com> Date: Sat, 17 Apr 2021 16:56:35 +0300 Message-ID: <8735vpf20c.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210417_065648_036510_036D444C X-CRM114-Status: GOOD ( 13.24 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Yicong Yang writes: > The reason for not using perf is because there is no current support > for uncore tracing in the perf facilities. Not unless you count $ perf list|grep -ic uncore 77 > We have our own format > of data and don't need perf doing the parsing. Perf has AUX buffers, which are used for all kinds of own formats. > A similar approach for implementing this function is ETM, which use > sysfs for configuring and a character device for dumping data. And also perf. One reason ETM has a sysfs interface is because the driver predates perf's AUX buffers. Can't say if it's the only reason. I'm assuming you're talking about Coresight ETM. > Greg has some comments on our implementation and doesn't advocate > to build driver on debugfs [1]. So I resend this series to > collect more feedbacks on the implementation of this driver. > > Hi perf and ETM related experts, is it suggested to adapt this driver > to perf? Or is the debugfs approach acceptable? Otherwise use Aside from the above, I don't think the use of debugfs for kernel ABIs is ever encouraged. Regards, -- Ale _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel