From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailgw1.hygon.cn (unknown [101.204.27.37]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1E4CE446C00; Tue, 18 Aug 2026 11:04:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=101.204.27.37 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787051099; cv=none; b=U10T5c8PowP7U2viqHkItpFmM9Ts2FWQIdqQQuqY9VooN4HH+O4DMBwLOo5EfEEmvO4a5wwKTEyzkZF0ljlq/lG/Wn35VJXms/9YHcTUoMvtQxP5Xe80lh44u8TQrR2pOg3/nuepJ0oC02TFGOmdDxrG3DG9cVZbGBB1L901rIg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787051099; c=relaxed/simple; bh=V8ozXke85QcC4BsoBiqOrhOzx3cKru052NYQPdFqNlE=; h=Date:From:To:CC:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=igCeGjatbCpd5oGySyzW/hDFMig7tRS5dwUkEL4j4QXHuNvR5XSbXd3f3r98FaBnaSbq7yaFvaXVRrTdFl+Ioz9p6hbWKp1ixZZhSmcP+1QWk11NsZWX9mBelCXMbE8CCaUWWDxRe/rpIfVlLI62Slt5n8LTklDM5y+1cGce/TE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=hygon.cn; spf=pass smtp.mailfrom=hygon.cn; arc=none smtp.client-ip=101.204.27.37 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=hygon.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=hygon.cn Received: from maildlp2.hygon.cn (unknown [127.0.0.1]) by mailgw1.hygon.cn (Postfix) with ESMTP id 4hPRfr2D9Dz1b69Q; Tue, 18 Aug 2026 19:04:36 +0800 (CST) Received: from maildlp2.hygon.cn (unknown [172.23.18.61]) by mailgw1.hygon.cn (Postfix) with ESMTP id 4hPRfp2wGnz1b69Q; Tue, 18 Aug 2026 19:04:34 +0800 (CST) Received: from cncheex04.Hygon.cn (unknown [172.23.18.114]) by maildlp2.hygon.cn (Postfix) with ESMTPS id 6A714300D1E7; Tue, 18 Aug 2026 19:01:08 +0800 (CST) Received: from hsj-2U-Workstation (172.19.24.226) by cncheex04.Hygon.cn (172.23.18.114) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Tue, 18 Aug 2026 19:04:33 +0800 Date: Tue, 18 Aug 2026 19:04:31 +0800 From: Huang Shijie To: Peter Zijlstra CC: Ravi Bangoria , , , , , , , , , , , , , , , , , , , , , Subject: Re: [RFC PATCH] perf/amd/ibs: Report physical address for IBS fetch samples Message-ID: References: <20260817073323.2504767-1-huangsj@hygon.cn> <9a39e681-3184-4841-9e19-7fc40956e917@amd.com> <20260818080024.GB1247881@noisy.programming.kicks-ass.net> <638cf844-8422-4706-b028-60d8722ce487@amd.com> <20260818091913.GD1247881@noisy.programming.kicks-ass.net> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20260818091913.GD1247881@noisy.programming.kicks-ass.net> X-ClientProxiedBy: cncheex05.Hygon.cn (172.23.18.115) To cncheex04.Hygon.cn (172.23.18.114) On Tue, Aug 18, 2026 at 11:19:13AM +0200, Peter Zijlstra wrote: > > >> > > >> PERF_SAMPLE_PHYS_ADDR is meant to capture the _data_ physical address, which > > >> IBS Fetch doesn't provide. So, repurposing semantics of PERF_SAMPLE_PHYS_ADDR > > >> for IBS Fetch seems reasonable. > > >> > > >> Reviewed-by: Ravi Bangoria > > > > > > Well, why confuse things? > > > > > > As you say, PHYS_ADDR is for ADDR, which is the *data* address, and > > > FETCH is an instruction address, which we find in IP, not DATA. > > > > > > What would be the purpose of confusing things and making PHYS_ADDR > > > relate to IP? > > > > Agreed, that would create confusion. > > > > Do you think we should introduce a new type PERF_SAMPLE_IP_PHYS_ADDR? > > I didn't suggest it earlier because I thought it would be overkill. > > Well, that all depends on how useful this data is. As is, I see very > little words on the benefit of having this data. I just use this patch to track a program's memory footprint, including the front-end(Fetch samples) and back-end(Op samples) in NUMA server. So I also think there is no need to add a PERF_SAMPLE_IP_PHYS_ADDR for this. Thanks Huang Shijie > > In fact, I'm not really sure what PHYS_ADDR is good for, so clearly I'm > missing a bit to begin with. > > That is; if there is a very convincing argument to actually have this > data, that might help justifying either accepting this 'hack' or perhaps > introducing more fields. >