From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (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 B11682E3398 for ; Fri, 14 Mar 2025 13:06:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741957573; cv=none; b=GhgQ+iG6bBrHV8MyuRMROL6HfIwG9fzhD/6Ss422TqGlyHVunOO5R5eOvZ6R5ic6lkXcYeqn2uQdK6CqdKlkAUKhFoKjqy5PLAfGBfRBkZEmutvCUJmhg09SRojO2XJLsoay9vM++rSIpeQ2dkkzN+dxxW/bV6rZt+Z/jvcj7rs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741957573; c=relaxed/simple; bh=5ykfQotWkvLY3QAFu6nKaTw+qHt85KWptUeqV8O95+Q=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=aMd8EsPJVJ6SHo2E2QLWeC/vFF97HvZDPU6vaXQXD/Rkudai61zkV9aXSW9k3FdKtKgJXKX+wDz90oozyL6AllP30Rv2QgHZpzDFbsMxpVgKhzGy5mTrc+L5kA7VxSIe8nG1l9j4meaDCeIQ5TqhzT+iqlDmGICN2o88QuH7fLQ= 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=WZkl0rIf; arc=none smtp.client-ip=192.198.163.11 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="WZkl0rIf" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1741957572; x=1773493572; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=5ykfQotWkvLY3QAFu6nKaTw+qHt85KWptUeqV8O95+Q=; b=WZkl0rIfoPkjdRVFq8tRtL8bVoMWmieqJAdicnSwRS4ZSgEOTrNf22br 1I22sekF93PD6GXBcXyfBgqM8/7hEF5of/jNsnBAfuItgryzToGXYYcP+ ML514JX/uZ4Vq3WduwD1PrBuDEFFweQk2I1Wfd2QHYwyJ1wci+NNyFSLD +CartfXxfkwBKSL7Z8tbprAeLQNds+jBCfYemAtUZ7f1sERQgqDJbF/fD rU5ZY2psZfBE5geDS82sHh8+/HkL8W2GaJayouN7ZsBn4AvGtRoTVzQ/I i6WCJELjCQ5iMPzwnaKKALxQhU4sjYXS1PQDLhkBhA9+DQC1mj57nXYPE Q==; X-CSE-ConnectionGUID: R1IcS2ZxTuK89kVbsAbeSQ== X-CSE-MsgGUID: X/RBbJhkSjCP/NzPga8ZXQ== X-IronPort-AV: E=McAfee;i="6700,10204,11373"; a="53761963" X-IronPort-AV: E=Sophos;i="6.14,246,1736841600"; d="scan'208";a="53761963" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Mar 2025 06:06:11 -0700 X-CSE-ConnectionGUID: buFAKAfyS5GFxeujkPvRXA== X-CSE-MsgGUID: ZNf8xV09RYyoCcFw6IrnKw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.14,246,1736841600"; d="scan'208";a="121778146" Received: from linux.intel.com ([10.54.29.200]) by orviesa007.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Mar 2025 06:06:12 -0700 Received: from [10.246.136.14] (kliang2-mobl1.ccr.corp.intel.com [10.246.136.14]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by linux.intel.com (Postfix) with ESMTPS id 89FA220B5736; Fri, 14 Mar 2025 06:06:09 -0700 (PDT) Message-ID: <108c7d02-257c-4131-a7f0-f9cb34ed3f5c@linux.intel.com> Date: Fri, 14 Mar 2025 09:06:07 -0400 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V2 0/3] Support auto counter reload To: Ingo Molnar Cc: peterz@infradead.org, acme@kernel.org, namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com, ak@linux.intel.com, linux-kernel@vger.kernel.org, eranian@google.com, thomas.falcon@intel.com References: <20241010192844.1006990-1-kan.liang@linux.intel.com> Content-Language: en-US From: "Liang, Kan" In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2025-03-14 5:51 a.m., Ingo Molnar wrote: > > * kan.liang@linux.intel.com wrote: > >> From: Kan Liang >> >> Changes since V1: >> - Add a check to the reload value which cannot exceeds the max period >> - Avoid invoking intel_pmu_enable_acr() for the perf metrics event. >> - Update comments explain to case which the event->attr.config2 exceeds >> the group size > >> The 2498 samples are all from the branch-misses events for the Loop 2. >> >> The number of samples and overhead is significantly reduced without >> losing any information. > > Ok, that looks like a pretty sweet PMU feature. > Thanks for the review. > What is the hardware support range of this auto count reload feature, > how recent CPU does one have to have? The feature was first introduced into the Sierra Forest server, which was launched last year. https://en.wikipedia.org/wiki/Sierra_Forest All the future platforms should have it support as well. > > The series has aged a bit though, while a variant of patch #1 has been > merged already under: > > 47a973fd7563 perf/x86/intel: Fix ARCH_PERFMON_NUM_COUNTER_LEAF > > ... but #2 and #3 don't apply cleanly anymore. > > Mind sending a refreshed series perhaps? No problem. I saw Peter just gives several feedback. I will also address the concerns in the new series. Thanks, Kan