From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C0FE1D8DFD for ; Fri, 24 Jan 2025 05:18:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737695937; cv=none; b=rau6BUjEdlHtknQMWNRk17+vttkMm5ibJjEi4wnNBn+S2rQlWZSNwF9034TDGeva5zwHiMzVFtNN5koHQYI2SfcGT5LYTUMm7AwEGvs4xV29mEsLhyhWvVXStYM8z9Y7MCTXDNc4WPSVFZ+02olWtaldDnKriZx5QsrWhdQWuT8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737695937; c=relaxed/simple; bh=+Nja++XjybK33emAZIStQX2F348+XXB5F8Zzx7YMheg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kkaOQcmMuaaLyLAiMRjUeLj4iUdr+F5rzR/h3Jew84vv9ZCthNV4YapCLr9m6dIKxjAxNaYHPal5CD3JitU48JnwOTpARlymUmXAfkX7nZSbTGz+ANHXwO0oqe1vIsxWa183xudK0ZvSG9OHRTv9aZPNW4mT0n5hftRwRYvbsxc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=cBGKyLJW; arc=none smtp.client-ip=192.198.163.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="cBGKyLJW" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1737695935; x=1769231935; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=+Nja++XjybK33emAZIStQX2F348+XXB5F8Zzx7YMheg=; b=cBGKyLJWZfZoaH1mrngYWpcH7PzAo+uOAUn+wzvF0GvwMY1R5pGlx6Ku 0e7E2jczy3vHd9iZwdE3pXTCi7tGAyhqcgQ2YNgfQbRG9XXlb7/zI5zVU LLmjzMXxpXmjGj8TZsKSxW4hVplocORspqazXuyiBcaFltC/7lYc1ewv5 +yOGmXeF8B0yotcqBvK6cmWaB54CYBFqypyQmSKW10SgBYFC3kC621OVT Seots4ap86Ex+DZ8yQLFKrz73VwQY7n4KTNDUFPMNqT400FZF8lr1fDDq hHLF84TksGDOK7dyWe27/imjon4g7v20vAHrM2w9ii4LT9bk0DznIQW34 A==; X-CSE-ConnectionGUID: aqYTsn48Rs2ZP8ZNIwgwKw== X-CSE-MsgGUID: 4ussRvhpSuOkQ6jVcadX7A== X-IronPort-AV: E=McAfee;i="6700,10204,11324"; a="41056274" X-IronPort-AV: E=Sophos;i="6.13,230,1732608000"; d="scan'208";a="41056274" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jan 2025 21:18:54 -0800 X-CSE-ConnectionGUID: TH+O9/t6QK+oLYnwvKQkog== X-CSE-MsgGUID: kRwUIYrfSi6rAdFamfJNIA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,224,1728975600"; d="scan'208";a="112306540" Received: from tassilo.jf.intel.com (HELO tassilo) ([10.54.38.190]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jan 2025 21:18:54 -0800 Date: Thu, 23 Jan 2025 21:18:53 -0800 From: Andi Kleen To: Vince Weaver Cc: Peter Zijlstra , "Liang, Kan" , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Adrian Hunter , linux-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com Subject: Re: perf: is it possible to userspace rdpmc but only on a certain core type Message-ID: References: <31ad367a-721f-46e7-8e5f-e96b250a8a32@linux.intel.com> <20250121125230.GD7145@noisy.programming.kicks-ass.net> <79462dc8-6f90-0d0b-1374-ac5123aa0f45@maine.edu> Precedence: bulk X-Mailing-List: linux-kernel@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: On Thu, Jan 23, 2025 at 02:45:33PM -0500, Vince Weaver wrote: > On Thu, 23 Jan 2025, Andi Kleen wrote: > > > > I have a student working on this for PAPI. If we get it working we can > > > see if perf could use support too if it doesn't have it already. > > > > perf user space doesn't have a ring 3 self access library. > > what happens if you're doing top-down measurments with perf on a hybrid > system and perf gets migrated to an E-core? > > or are you saying perf always uses a syscall to read the top-down values > and doesn't use rdpmc in that case? perf always uses system calls or mmap. -Andi