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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D578AECAAD8 for ; Thu, 22 Sep 2022 20:41:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229687AbiIVUln (ORCPT ); Thu, 22 Sep 2022 16:41:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229788AbiIVUlm (ORCPT ); Thu, 22 Sep 2022 16:41:42 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BDE610FE0F; Thu, 22 Sep 2022 13:41:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1663879301; x=1695415301; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=D6yUnrY2M8EW+DGeUBJpNdMW0BxKMc78VDaRnOgbaWU=; b=RwnUoBWPojPt/iMrpQnpryejn6knWyh9PxQ4wAeRn9oFpsolV5KNVoon ZLJoyAYUvBCq+FoLt1Xp1gEfrK1Sll8p3Wj2c27a48ngwAib7EF8oLEHj zvaabeMdCBwEWTz8knScopINK1jugNqubaOjIjg1Xy7J5c+2dfw3vCNJS yYZ65Vot+tR2pmCgik430gbdkl9XjtoJXmgxwU+K27SySyNp4RiukxXhd rHHUAZlPuJKDHMilVaByXrtjHBdP48w8JZOWN6Wlbc3kJuLZiWGbD3z/j tS4BczZ7u80cjMFDhwtfTkewVyS+QiGkKUhYKwqzaPlxBshArMSWgF7N/ A==; X-IronPort-AV: E=McAfee;i="6500,9779,10478"; a="287537028" X-IronPort-AV: E=Sophos;i="5.93,337,1654585200"; d="scan'208";a="287537028" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Sep 2022 13:41:41 -0700 X-IronPort-AV: E=Sophos;i="5.93,337,1654585200"; d="scan'208";a="615366023" Received: from djiang5-mobl2.amr.corp.intel.com (HELO [10.212.80.137]) ([10.212.80.137]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Sep 2022 13:41:40 -0700 Message-ID: <60048f0f-eb51-99bc-14fc-1974442ab454@intel.com> Date: Thu, 22 Sep 2022 13:41:39 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.3.0 Subject: Re: [RFC PATCH v2 4/4] docs: perf: Minimal introduction the the CXL PMU device and driver. Content-Language: en-US To: Jonathan Cameron , linux-cxl@vger.kernel.org, Dan Williams , Alison Schofield , Vishal Verma , Ira Weiny , Ben Widawsky , linux-perf-users@vger.kernel.org, Will Deacon , Mark Rutland Cc: linuxarm@huawei.com References: <20220824103617.21781-1-Jonathan.Cameron@huawei.com> <20220824103617.21781-5-Jonathan.Cameron@huawei.com> From: Dave Jiang In-Reply-To: <20220824103617.21781-5-Jonathan.Cameron@huawei.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On 8/24/2022 3:36 AM, Jonathan Cameron wrote: > Very basic introduction to the device and the current driver support > provided. I expect to expand on this in future versions of this patch > set. > > Signed-off-by: Jonathan Cameron > > -- > RFC: > - I'll post separately about this shortly, but it seems very odd > to me that there is no way to assign a parent to an event_sources > device. As a result we get the messy approach of playing match > the name to figure out what the CPMU instance is connected to. > --- > Documentation/admin-guide/perf/cxl.rst | 60 ++++++++++++++++++++++++ > Documentation/admin-guide/perf/index.rst | 1 + > 2 files changed, 61 insertions(+) > > diff --git a/Documentation/admin-guide/perf/cxl.rst b/Documentation/admin-guide/perf/cxl.rst > new file mode 100644 > index 000000000000..6ffc057591fb > --- /dev/null > +++ b/Documentation/admin-guide/perf/cxl.rst > @@ -0,0 +1,60 @@ > +====================================== > +CXL Performance Monitoring Unit (CPMU) > +====================================== > + > +The CXL rev 3.0 specification provides a definition of CXL Performance > +Monitoring Unit in section 13.2: Performance Monitoring. > + > +CXL components (e.g. Root Port, Switch Upstream Port, End Point) may have > +any number of CPMU instances. CPMU capabilities are fully discoverable from > +the devices. The specification provides event definitions for all CXL protocol > +message types and a set of additional events for things commonly counted on > +CXL devices (e.g. DRAM events). > + > +CPMU driver > +=========== > + > +The CPMU driver register a perf PMU with the name cpmu on the CXL bus. > + > + /sys/bus/cxl/device/cpmu > + > +The associated PMU is registered as > + > + /sys/bus/event_sources/devices/cpmu > + > +In common with other CXL bus devices, the id has no specific meaning and the > +relationship to specific CXL device should be established via the device parent > +of the device on the CXL bus. > + > +PMU driver provides description of available events and filter options in sysfs. > + > +The "format" directory describes all formats of the config (event vendor id, > +group id and mask) config1 (threshold, filter enables) and config2 (filter > +parameters) fields of the perf_event_attr structure. The "events" directory > +describes all documented events show in perf list. "all the documented events shown in perf list." DJ > + > +The events shown in perf list are the most fine grained events with a single > +bit of the event mask set. More general events may be enable by setting > +multiple mask bits in config. For example, all Device to Host Read Requests > +may be captured on a single counter by setting the bits for all of > + > +* d2h_req_rdcurr > +* d2h_req_rdown > +* d2h_req_rdshared > +* d2h_req_rdany > +* d2h_req_rdownnodata > + > +Example of usage:: > + > + $#perf list > + cpmu0/clock_ticks/ [Kernel PMU event] > + cpmu0/d2h_req_itomwr/ [Kernel PMU event] > + cpmu0/d2h_req_rdany/ [Kernel PMU event] > + cpmu0/d2h_req_rdcurr/ [Kernel PMU event] > + ----------------------------------------------------------- > + > + $# perf stat -e cpmu0/clock_ticks/ -e cpmu0/d2h_req_itowrm/ > + > +The driver does not support sampling. So "perf record" and attaching to > +a task are unsupported. > + > diff --git a/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst > index 9c9ece88ce53..f12cfe76e1f0 100644 > --- a/Documentation/admin-guide/perf/index.rst > +++ b/Documentation/admin-guide/perf/index.rst > @@ -18,3 +18,4 @@ Performance monitor support > xgene-pmu > arm_dsu_pmu > thunderx2-pmu > + cxl