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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF57BC433EF for ; Wed, 13 Apr 2022 17:09:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 23AE46B0074; Wed, 13 Apr 2022 13:09:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1EADE6B0075; Wed, 13 Apr 2022 13:09:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0B3706B0078; Wed, 13 Apr 2022 13:09:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id F05C36B0074 for ; Wed, 13 Apr 2022 13:09:29 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay11.hostedemail.com (Postfix) with ESMTP id A966C824C1 for ; Wed, 13 Apr 2022 17:09:29 +0000 (UTC) X-FDA: 79352492058.17.248DD42 Received: from mail-wr1-f50.google.com (mail-wr1-f50.google.com [209.85.221.50]) by imf29.hostedemail.com (Postfix) with ESMTP id 3906312000F for ; Wed, 13 Apr 2022 17:09:29 +0000 (UTC) Received: by mail-wr1-f50.google.com with SMTP id p18so2744495wru.5 for ; Wed, 13 Apr 2022 10:09:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=sCLiXto+N+uwNvwTzKfo+TPPGQjP4GFjpgB4ZdDzCwA=; b=MkZiwQvVjG36q8ePnIhm0w66YSzngKvc5oJJvnJmsCef4T9vJ6aWRANmip/0NJLen6 Aia72rjrqEleWdmX6pp3m/yfvg73D3lay36uWX/HHWfiSGnP+w8muJCzanM0t1Qh3jXZ B7t3CTpV0YGIj9DrkuSuoRO0bE8j0ISFDKY2BTME0vbFx7WaCjTtyA86PjVSCxdzkgsz 9OhxuHhJ4K0VnzzNd8GGbWSycQfaVMqKzkVa5HH8lzy3QWHJijb997UNs4tHZkCg28gm gsiRN9GK5c5CV84U6usdPEGTUBYyFth1FY3xE7NHbPPRnFHJG03oKTQZoRA7eUea2rnF YxQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=sCLiXto+N+uwNvwTzKfo+TPPGQjP4GFjpgB4ZdDzCwA=; b=MWPm20qyBNPAIiSa0J4uK9zWH1VCbhbP7+reucJBxegTBTIyLSTrSAd2Sw3IrYrP9s m4+mby3DMjF+veVg4WjylJo6zMDS3gfVVciRlqFJkbmfXR8IDfUDNgLYprU/YLvvUtUE /35sfTwT8etDYRGprL8qNdi4XdIq20ToUo65jxz0gIbCdxzgyIujT0WslhwJQJHP/o+5 aY0GWFuiWkyjsIcp5MSstZZQfy31wockfSf00QuYf22YWHSdDXmCqVIifhSnLv4pYuGY eB2IbwteGOCMzh+sFaiRSltO1hNWS5ENZSdqwKAEqOJzmGDLm9F9UMta0pNFbRpi8+df nkvQ== X-Gm-Message-State: AOAM532bfTvoBkMFG51OB7+YNPetSfuHKp+4xQHG3EZUJqZ8CQxM6wIg pLY0RPOb43gaNXjfDXwhVK5yLGzjDMypOukpCRBQcQ== X-Google-Smtp-Source: ABdhPJyli41f+i1rwTLIV2MJwxxgzzWw7Zz26GHsP9cvbLAt8rnThx1uAQV/lOxtF/JQ0NQPCAtI5c8ohWYReiCK+hU= X-Received: by 2002:a5d:6241:0:b0:207:ac0e:3549 with SMTP id m1-20020a5d6241000000b00207ac0e3549mr9032063wrv.343.1649869767586; Wed, 13 Apr 2022 10:09:27 -0700 (PDT) MIME-Version: 1.0 References: <20220304083329.GC20556@xsang-OptiPlex-9020> <20220413070529.GA1320@linux.intel.com> <85eed89f-e4a8-2887-a0b3-579704304357@linux.intel.com> In-Reply-To: <85eed89f-e4a8-2887-a0b3-579704304357@linux.intel.com> From: Ian Rogers Date: Wed, 13 Apr 2022 10:09:15 -0700 Message-ID: Subject: Re: [LKP] Re: [perf vendor events] 3f5f0df7bf: perf-sanity-tests.perf_all_metrics_test.fail To: "Liang, Kan" Cc: Carel Si , acme@redhat.com, alexander.shishkin@linux.intel.com, alexandre.torgue@foss.st.com, ak@linux.intel.com, mingo@redhat.com, james.clark@arm.com, jolsa@kernel.org, john.garry@huawei.com, mark.rutland@arm.com, mcoquelin.stm32@gmail.com, namhyung@kernel.org, peterz@infradead.org, eranian@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lkp@lists.01.org, lkp@intel.com Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 3906312000F X-Stat-Signature: pjzxqn8jah5axo1raxhrrx5cys3p4bnh Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=MkZiwQvV; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf29.hostedemail.com: domain of irogers@google.com designates 209.85.221.50 as permitted sender) smtp.mailfrom=irogers@google.com X-Rspam-User: X-HE-Tag: 1649869769-415737 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Apr 13, 2022 at 9:37 AM Liang, Kan wrote: > > > > On 4/13/2022 12:03 PM, Ian Rogers wrote: > > 3) Weak group doesn't fall back to no group: > > That's because the group validation code doesn't take pinned events, > such as the NMI watchdog, into account. > > I proposed a kernel patch to fix it, but it's rejected. It should be > hard to find a generic way to fix it from the kernel side. > https://lore.kernel.org/lkml/1565977750-76693-1-git-send-email-kan.liang@linux.intel.com/ > > Maybe we can workaround it from the perf tool side? > For example, for each weak group with cycles event and NMI watchdog is > enabled, add an extra cycles event when opening the group. If the open > fails with the extra cycles event, fall back to no group. After the > extra cycles event check, remove the extra cycles. > > What do you think? Thanks Kan, it is a shame the kernel support is lacking here. I'm not sure what you are proposing for the perf tool to do. So: > for each weak group with cycles event and NMI watchdog Okay, let's try Branching_Overhead as mentioned in this report - but the event is CPU_CLK_UNHALTED.THREAD here :-/ > add an extra cycles event when opening the group So the perf_event_open doesn't fail here for me: $ perf stat -e '{BR_INST_RETIRED.NEAR_CALL,BR_INST_RETIRED.NEAR_TAKEN,BR_INST_RETIRED.NOT_TAKEN,BR_INST_RETIRED.CONDITIONAL,CPU_CLK_UNHALTED.THREAD},cycles' -a sleep 1 Performance counter stats for 'system wide': BR_INST_RETIRED.NEAR_CALL (0.00%) BR_INST_RETIRED.NEAR_TAKEN (0.00%) BR_INST_RETIRED.NOT_TAKEN (0.00%) BR_INST_RETIRED.CONDITIONAL (0.00%) CPU_CLK_UNHALTED.THREAD (0.00%) 4,071,908,022 cycles (49.97%) 0.998134717 seconds time elapsed Some events weren't counted. Try disabling the NMI watchdog: echo 0 > /proc/sys/kernel/nmi_watchdog perf stat ... echo 1 > /proc/sys/kernel/nmi_watchdog The events in group usually have to be from the same PMU. Try reorganizing the group. I'm not sure what the cycles event is achieving here, but it seems the behavior will need a kernel change. I think I'm misunderstanding your proposal :-) Thanks, Ian > Thanks, > Kan > > $ perf stat -e '{BR_INST_RETIRED.NEAR_CALL,BR_INST_RETIRED.NEAR_TAKEN,BR_INST_RETIRED.NOT_TAKEN,BR_INST_RETIRED.CONDITIONAL,CPU_CLK_UNHALTED.THREAD}:W' > > -a sleep 1 > > > > Performance counter stats for 'system wide': > > > > BR_INST_RETIRED.NEAR_CALL > > (0.00%) > > BR_INST_RETIRED.NEAR_TAKEN > > (0.00%) > > BR_INST_RETIRED.NOT_TAKEN > > (0.00%) > > BR_INST_RETIRED.CONDITIONAL > > (0.00%) > > CPU_CLK_UNHALTED.THREAD > > (0.00%) > > > > 1.001690318 seconds time elapsed > > > > Some events weren't counted. Try disabling the NMI watchdog: > > echo 0 > /proc/sys/kernel/nmi_watchdog > > perf stat ... > > echo 1 > /proc/sys/kernel/nmi_watchdog