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 2803C13E8BF; Tue, 4 Jun 2024 20:01:44 +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=1717531306; cv=none; b=Fr+chZ/O0YI9rkTFjxWn7IFY8tGjQwqMntMchL8srHimMuOtq1r9FxsCOy/wA+pJxiHy0Vvwgs6JcLIes3FTuIC9oBQd53BvB8w4lEiGvoexE363qcGq5LX6IYuFBgbpZ947neLIEtQ7FwIHRMuQeNOLm7wyc2aRndnjsAE6Wj0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717531306; c=relaxed/simple; bh=RAw2k4mzU8OEDpDAeN6B2j6vr4BCw4gc3iGeitqWH58=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tGmnAmwtcBmNE07f+U1YnsG+O59CpaYhLd3XXz3pnCLJoAWX1gBGJzcTNFTK/3RCNZcz/q4j0wDdpbKj/pitec6TEo4JC0FGCd/GD4UnV29AqzdXag8gIh0CQNFKSz8/SNZQWakdHkruR7beef6jQ5UAFKYSjPHaK6V2feZl+iE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=foss.arm.com; spf=none smtp.mailfrom=foss.arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=foss.arm.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=foss.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 54970FEC; Tue, 4 Jun 2024 13:02:08 -0700 (PDT) Received: from [10.2.76.71] (e132581.arm.com [10.2.76.71]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8F6D83F64C; Tue, 4 Jun 2024 13:01:42 -0700 (PDT) Message-ID: Date: Tue, 4 Jun 2024 21:01:41 +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: [RFC/PATCH 1/1] tools headers arm64: Sync arm64's cputype.h with the kernel sources To: Mark Rutland Cc: Arnaldo Carvalho de Melo , Besar Wicaksono , Will Deacon , Adrian Hunter , Ian Rogers , Jiri Olsa , Kan Liang , Namhyung Kim , Linux Kernel Mailing List , linux-perf-users@vger.kernel.org, James Clark References: Content-Language: en-US From: Leo Yan In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 6/4/24 19:55, Mark Rutland wrote: [...] >> Now more and more Arm CPUs support the data source in SPE and share the same >> data source format. It's not scalable for us to adding every CPU variant >> into the file util/arm-spe.c. >> >> I would like to expose the PMSIDR_EL1.LDS bit (Data source indicator for >> sampled load instructions) via the 'cap' folder, and then we can save this >> info into the perf meta data during record phase. > > I'd be happy to expose fields from PMSIDR_EL1. > >> In the perf report, we can parse the meta data and if the >> PMSIDR_EL1.LDS bit is set, the tool will parse the data source packet >> based on the common format. > > I don't believe that's right. > > PMSIDR_EL1.LDS indicates that the loaded data source field is > implemented, but even when it is implemented, the format is > IMPLEMENTATION DEFINED. Thanks for correction. PMSIDR_EL1.LDS bit is necessary but not sufficient for using the common data source format. > Today, Arm Ltd implementations happen to share a format, but that isn't > implied by PMSIDR_EL1.LDS, and there's no guarantee that future CPUs > will all use the same format. > > For the moment we'll have to keep adding to this list. I would like to use an opposite way - we can only maintain CPU variants with special data source format, otherwise, all other CPUs use the common format. Thanks, Leo