From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 98944152781 for ; Tue, 30 Apr 2024 14:36:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714487768; cv=none; b=kWvTlxPefymtyacccyCZPIOYW2mwMx3WOnJ/DnowFo9JQmsTnkmym2QNI6Q/TSqd+drfktwfZCrWLZSolH5SeDDpK6pvd+fxOCqr/9It3719Z0fgDlHwkHVJAv3gdaV3b/h8HpV50xclD64rxqKK6B6UvFfjSsnl9H37Ik3+rVY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714487768; c=relaxed/simple; bh=9dqN/aRWuNLVid6/A9CDN4qIxnMtFET3MrRfW067klg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Nkw6S1/gUTElBDuTlgaAo87qK2ZY5RKnJrJ4eyorABfyF1drQx/DC3z9D9uJq/KDMcvq6o4Ut4UNcsvAClOrjxrsfZ5YvnhKghn11DJolDhXxzIdHbmR7d6H44BJm+KyUbfFusDpYfhb23EKMa4tfNnCFiXal6AO92S0GXRVXow= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 419EE339; Tue, 30 Apr 2024 07:36:32 -0700 (PDT) Received: from [192.168.1.100] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 679683F793; Tue, 30 Apr 2024 07:36:04 -0700 (PDT) Message-ID: <40bd4bb1-a2fa-4173-aea8-8ccd3ca23df3@arm.com> Date: Tue, 30 Apr 2024 15:36:02 +0100 Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Question about using the perf c2c in UMA system To: Ian Rogers , Leo Yan Cc: "?????? (Baisheng Gao)" , "jolsa@kernel.org" , "linux-perf-users@vger.kernel.org" , "???? (Hao_hao Wang)" References: <80f723d230744bc299044cfd4f8c4d92@shmbx06.spreadtrum.com> <20240429214321.GB125@debian-dev> Content-Language: en-US From: James Clark In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 30/04/2024 04:40, Ian Rogers wrote: > On Mon, Apr 29, 2024 at 2:43 PM Leo Yan wrote: >> >> Hi Baisheng, >> >> On Mon, Apr 08, 2024 at 10:52:59AM +0000, ?????? (Baisheng Gao) wrote: >>> Hi linux-perf-users, >>> >>> My perf tool version is 6.6, and I compiled it to run on an Android system. >>> The problem is: >>> >>> # ./perf c2c report >>> Failed setup nodes >>> >>> According to the articles on the Internet, it seems that the perf c2c is only supported >>> in NUMA system. However, the cache false sharing does not exist only in NUMA, and >>> the UMA system has also the problem. So I wonder how to support perf c2c in UMA. >> >> The log above is related with parsing NUMA nodes, but this doesn't >> mean 'perf c2c' must run on NUMA system. My understanding is both >> x86_64 (memory event) and Arm64 (SPE) support 'perf c2c' not only on >> NUMA. > > The lack of SPE on most ARM hardware really is a pain. Can we add a > better error message to make it clearer to users that they need a > neoverse CPU? :-) > This issue seems to be about report rather than record, so I'm assuming that the record worked and SPE is present. Having said that, the error message for no SPE isn't great, but it's not that bad either: $ perf c2c record failed: no PMU supports the memory events