From patchwork Tue Apr 11 18:54:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 82148 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b0ea:0:b0:3b6:4342:cba0 with SMTP id b10csp2792355vqo; Tue, 11 Apr 2023 12:02:46 -0700 (PDT) X-Google-Smtp-Source: AKy350Zxw1atze9E2XuBlvKUK7FiQayo8tfomCRblHVte+cL11ntifbfw/eb7/TsRAoG2bjPoWFS X-Received: by 2002:aa7:cd96:0:b0:502:70e9:2c14 with SMTP id x22-20020aa7cd96000000b0050270e92c14mr3054035edv.29.1681239765565; Tue, 11 Apr 2023 12:02:45 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1681239765; cv=none; d=google.com; s=arc-20160816; b=tkt3idvUNKLHd+15COGIx0xoMm06WjPN6lzoNsrJ+UJ11XcNgkn1pFCz7COOPuOOn2 Xm+pTh/EII10j/GISWmdvbDconLRNpwDqNdj8RvgHefZtpR0Uiv5v6UYUpuV0zKDuA0y kRSotlziestRb5NtxLyQ0MFytfx21oza2YVzZ1jUxJAHA7EpeOm3g1m3BOshTRrQxCzZ NrP8B8pR2qMB+EV6jlnIBmQAJPft9i1IBxYhR6vbNjiYOzoaXk1N1qEdmfaZDdin7sJm NkoVYNxFaI9OLEhXPHnVVn+zzse8DaRq1QE0SHvvaDE9Aqsrt6sgqRDpWk9c1QZde3/I 8BpA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from; bh=rvi2ZNdeTycDsZNSE88hROh4Tzyv+qlpXNGDWSdH83E=; b=I5VUhyer+nqhw1qdhh4Cx0XnMHYcVw6FHKq9F+T+49tgA36BswBg+Sxzh9nYq4D8IY H2LHUoTzoB95x72vKwUexv7Ut2zqIz+BNArAi2mH9jo0fLmEqeBfb/kc0RKhvLEiiNdv HVvTmurdxADy9L/RdQ3opcJcsplhaHb0sR3TFAY2aQKr1NKHLtJConsMDTxU6Lg8rU+4 85KCq14GsK/pdokaanblLIte/ZRLV7WajbRvbz4WoOqqYQ3E3f+214NdzLMEACngbnJ/ g3xA7By87/p6RFretFxNKB9+UGBFXxCkaG7D6fFKcqhlKQlBPCnTZw6HntXkpgYz1tox I7vg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=huawei.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id ka10-20020a170907990a00b00949581a32eesi523107ejc.1008.2023.04.11.12.02.20; Tue, 11 Apr 2023 12:02:45 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=huawei.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229458AbjDKS5e (ORCPT + 99 others); Tue, 11 Apr 2023 14:57:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229437AbjDKS5d (ORCPT ); Tue, 11 Apr 2023 14:57:33 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B9C618C; Tue, 11 Apr 2023 11:57:27 -0700 (PDT) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4Pww551qfcz6J70L; Wed, 12 Apr 2023 02:55:05 +0800 (CST) Received: from SecurePC-101-06.china.huawei.com (10.122.247.231) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Tue, 11 Apr 2023 19:57:24 +0100 From: Jonathan Cameron To: Liang Kan , , , , CC: , , , , , , Davidlohr Bueso , Dave Jiang Subject: [PATCH v5 5/5] docs: perf: Minimal introduction the the CXL PMU device and driver Date: Tue, 11 Apr 2023 19:54:52 +0100 Message-ID: <20230411185452.23387-6-Jonathan.Cameron@huawei.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20230411185452.23387-1-Jonathan.Cameron@huawei.com> References: <20230411185452.23387-1-Jonathan.Cameron@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.122.247.231] X-ClientProxiedBy: lhrpeml500004.china.huawei.com (7.191.163.9) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-2.3 required=5.0 tests=RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1762907668089526357?= X-GMAIL-MSGID: =?utf-8?q?1762907668089526357?= 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. Reviewed-by: Dave Jiang Signed-off-by: Jonathan Cameron Reviewed-by: Kan Liang --- v5: - Correct final statemnt about sampling support. (Kan) - Update CXL PMU MAINTAINERS entry to include this documentation - Update device naming to cxl_pmu_memX.Y etc --- Documentation/admin-guide/perf/cxl.rst | 68 ++++++++++++++++++++++++ Documentation/admin-guide/perf/index.rst | 1 + MAINTAINERS | 1 + 3 files changed, 70 insertions(+) diff --git a/Documentation/admin-guide/perf/cxl.rst b/Documentation/admin-guide/perf/cxl.rst new file mode 100644 index 000000000000..2a1c684603bb --- /dev/null +++ b/Documentation/admin-guide/perf/cxl.rst @@ -0,0 +1,68 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====================================== +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 registers a perf PMU with the name pmu_mem. on the CXL bus +representing the Yth CPMU for memX. + + /sys/bus/cxl/device/pmu_mem. + +The associated PMU is registered as + + /sys/bus/event_sources/devices/cxl_pmu_mem. + +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. + +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 + cxl_pmu_mem0.0/clock_ticks/ [Kernel PMU event] + cxl_pmu_mem0.0/d2h_req_rdshared/ [Kernel PMU event] + cxl_pmu_mem0.0/h2d_req_snpcur/ [Kernel PMU event] + cxl_pmu_mem0.0/h2d_req_snpdata/ [Kernel PMU event] + cxl_pmu_mem0.0/h2d_req_snpinv/ [Kernel PMU event] + ----------------------------------------------------------- + + $# perf stat -e cxl_pmu_mem0.0/clock_ticks/ -e cxl_pmu_mem0.0/d2h_req_rdshared/ + +Vendor specific events may also be available and if so can be used via + + $# perf stat -e cxl_pmu_mem0.0/vid=VID,gid=GID,mask=MASK/ + +The driver does not support sampling so "perf record" is unsupported. +It only supports system-wide counting so attaching to a task is +unsupported. diff --git a/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst index 9de64a40adab..f60be04e4e33 100644 --- a/Documentation/admin-guide/perf/index.rst +++ b/Documentation/admin-guide/perf/index.rst @@ -21,3 +21,4 @@ Performance monitor support alibaba_pmu nvidia-pmu meson-ddr-pmu + cxl diff --git a/MAINTAINERS b/MAINTAINERS index 51234eb7858e..29a108afa065 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5178,6 +5178,7 @@ COMPUTE EXPRESS LINK PMU (CPMU) M: Jonathan Cameron L: linux-cxl@vger.kernel.org S: Maintained +F: Documentation/admin-guide/perf/cxl.rst F: drivers/perf/cxl_pmu.c CONEXANT ACCESSRUNNER USB DRIVER