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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 49A1EC7EE2F for ; Mon, 5 Jun 2023 07:10:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=hG3cmoUB2qT6KgreWRRmHp3Ge5yJvWaC266f2T1TcPs=; b=3ZKaILX1Dsxw1Z ZEVDwIK20I+dbcPwR9DJPk+g2ghdW0OKxyc6MAWYT4Gx2ZMHwR38FS9facSiQnpQxyRCns5ipH9uW uTFknS5NIP/hLL+n5ffgLLrYh1qycHfW7NsA1mSWQ8lDdxcPbDX5jea8WVeG7NjEbG0KVikicqzun b/lPlCabR+eDR6LB3wARTqQKn/fx7nGL/8/EZe9KxZ+4jew8Amt50yb+yvM7bx5DVbM2nSphUlY49 m3gY2x5VmsVOHEOwdR5lylJvkp/n30+VvqRiIhnnaCQEE1OBnThYV64giF+L6j+oz6a9RWWN25Z9V OJr3wI2sNxgVOgKo+K4Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q64MG-00EVVE-0l; Mon, 05 Jun 2023 07:10:28 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1q64MC-00EVUL-1k for linux-arm-kernel@lists.infradead.org; Mon, 05 Jun 2023 07:10:26 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8936DD75; Mon, 5 Jun 2023 00:11:08 -0700 (PDT) Received: from FVFF77S0Q05N (unknown [10.57.24.244]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1C0223F793; Mon, 5 Jun 2023 00:10:20 -0700 (PDT) Date: Mon, 5 Jun 2023 08:10:15 +0100 From: Mark Rutland To: Krzysztof Kozlowski , Ravi Bangoria , "Peter Zijlstra (Intel)" Cc: jolsa@kernel.org, irogers@google.com, bp@alien8.de, adrian.hunter@intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, "linux-samsung-soc@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "regressions@lists.linux.dev" Subject: Re: [REGRESSION][BISECT] perf/core: Remove pmu linear searching code Message-ID: References: <3abd3693-ad87-9abf-a762-337076638fcc@linaro.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <3abd3693-ad87-9abf-a762-337076638fcc@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230605_001024_624576_19080FB1 X-CRM114-Status: GOOD ( 13.27 ) 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 On Sun, Jun 04, 2023 at 01:38:10PM +0200, Krzysztof Kozlowski wrote: > Hi, > > #regzbot introduced: 9551fbb64d09 > > Bisect pointed to commit 9551fbb64d09 ("perf/core: Remove pmu linear > searching code") as first one where all hardware events are gone from > perf for ARMv7 Exynos5422 board. I think that commit 9551fbb64d09 is just wrong. The commit message asserts: Searching for the right pmu by iterating over all pmus is no longer required since all pmus now *must* be present in the 'pmu_idr' list. So, remove linear searching code. ... and while each PMU has *some* entry in the pmu_idr list, for its dynamic type, that means that events with other types (e.g. PERF_TYPE_HARDWARE or PERF_TYPE_RAW) will fail to find a PMU in the IDR whereas they'd previously have been accepted by a PMU during the subsequent iteration over all PMUs. So that iteration is still required. How does this work on x86? Do you have pseudo-PMUs for PERF_TYPE_HARDWARE and PERF_TYPE_RAW ? Thanks, Mark. > Expected: > perf list | grep "Hardware event" > branch-instructions OR branches [Hardware event] > branch-misses [Hardware event] > bus-cycles [Hardware event] > cache-misses [Hardware event] > cache-references [Hardware event] > cpu-cycles OR cycles [Hardware event] > instructions [Hardware event] > > > Result: > empty, no hardware events > > 1. Arch ARM Linux > 2. exynos_defconfig > 3. Board: > - Odroid HC1 > ARMv7, octa-core (Cortex-A7+A15), Exynos5422 SoC > Systemd: v239 > > 4. perf version 6.1.0 > > > Best regards, > Krzysztof _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel