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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 68432C3F2C6 for ; Tue, 3 Mar 2020 19:07:52 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id E3AAD208C3 for ; Tue, 3 Mar 2020 19:07:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E3AAD208C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 45CC74AEE4; Tue, 3 Mar 2020 14:07:51 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id LX6rY9zXUcZV; Tue, 3 Mar 2020 14:07:50 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 30E084AEED; Tue, 3 Mar 2020 14:07:50 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id EEE074AEE4 for ; Tue, 3 Mar 2020 14:07:48 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id WF0he-wo-SeO for ; Tue, 3 Mar 2020 14:07:47 -0500 (EST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mm01.cs.columbia.edu (Postfix) with ESMTP id C38464AEE1 for ; Tue, 3 Mar 2020 14:07:47 -0500 (EST) 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 4B45230E; Tue, 3 Mar 2020 11:07:47 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 695463F534; Tue, 3 Mar 2020 11:07:46 -0800 (PST) Date: Tue, 3 Mar 2020 19:07:44 +0000 From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Subject: Re: [PATCHv6 0/3] arm64: perf: Add support for ARMv8.5-PMU 64-bit counters Message-ID: <20200303190742.GD7649@lakrids.cambridge.arm.com> References: <20200302181752.14251-1-mark.rutland@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200302181752.14251-1-mark.rutland@arm.com> User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) Cc: catalin.marinas@arm.com, will@kernel.org, kvmarm@lists.cs.columbia.edu, maz@kernel.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Mon, Mar 02, 2020 at 06:17:49PM +0000, Mark Rutland wrote: > This is a respin of Andrew Murray's series to enable support for 64-bit > counters as introduced in ARMv8.5. > > I've given this a spin on (ARMv8.2) hardware, to test that there are no > regressions, but I have not had the chance to test in an ARMv8.5 model (which I > beleive Andrew had previously tested). Bad news; this is broken. :( While perf-stat works as expected, perf-record doesn't get samples for any of the programmable counters. In ARMv8.4 mode I can do: | / # perf record -a -c 1 -e armv8_pmuv3/inst_retired/ true | [ perf record: Woken up 1 times to write data ] | [ perf record: Captured and wrote 0.023 MB perf.data (367 samples) ] | / # perf record -a -c 1 -e armv8_pmuv3/inst_retired,long/ true | [ perf record: Woken up 1 times to write data ] | [ perf record: Captured and wrote 0.022 MB perf.data (353 samples) ] ... so regular 32-bit and chained events work correctly. But in ARMv8.5 mode I get no samples in either case: | / # perf record -a -c 1 -e armv8_pmuv3/inst_retired/ true | [ perf record: Woken up 1 times to write data ] | [ perf record: Captured and wrote 0.008 MB perf.data ] | / # perf report | grep samples | Error: | The perf.data file has no samples! | / # perf record -a -c 1 -e armv8_pmuv3/inst_retired,long/ true | [ perf record: Woken up 1 times to write data ] | [ perf record: Captured and wrote 0.008 MB perf.data ] | / # perf report | grep samples | Error: | The perf.data file has no samples! I'll have to trace the driver to see what's going on. I suspect we've missed some bias handling, but it's possible that this is a model bug. Thanks, Mark. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm