From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) (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 4668B35336E; Wed, 20 Aug 2025 05:44:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755668684; cv=none; b=UNL1WhmjvZAlGAPHi/Klpv/aUSsOrFPCmS0YFFODLE/Bl+xnP47PVqsPLz2TqM9gxQ8cwN5hetsKdUp2Fnvf3zqQX19uF1EblMMNVMQpGWhm20g+AWNhwZP7FQ8G4AzdUueH7srYBppX7jjyaH9yY3tCm6A+jwO2zO0Zrk5MNlU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755668684; c=relaxed/simple; bh=CG+3hWSdQblLlzUPHzF5sZZBhRC8Uyqp/2xytibp9dM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QnAcVGn5wWgumvx593hpgso2BConB7wuQ8NMESNK6inN2bOX80wqMX0qjOuNShxl3ochaDtLKJzteH6qJiWi4AxScrNfFvFzfTjd8e9a+yKj0bxdRCDvxBUMHHvFhcfJzgQ/j7Xq3jXl4jR7JRvVd6ZPL6S0743j31VlYNxFJrg= 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=nkHHoqj9; arc=none smtp.client-ip=198.175.65.13 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="nkHHoqj9" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1755668683; x=1787204683; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=CG+3hWSdQblLlzUPHzF5sZZBhRC8Uyqp/2xytibp9dM=; b=nkHHoqj9p5TcG0bEk7K7lyOcM2Gt8STwV+HTcQ9xlQCdPP75SAbXEpOA hjfhmikrWhH5DJ3O8WnBytbdZhti7K3py51kKVvXGHn6ln27rAMS6eiKp oX/ljCJrSyMFjHYBa+rSFN3Y76Z3Z7BVwsGSkcei5uCMcEfr/ZJZhu/ui t6vmmXXIN7iLot/AvtPddRLrkDwNsh994ukFg+lzOsN3/nIuWurboQNR/ U1KmRMUAcIQARlOalLjDOtURVoWNwhGYbYQXF6QjbWO2C1Xv6R6PEYy3Z ZxMGSPi9k7svENcgWAgjZRWvNFUgXPKlrbo1CgNZ4AuRvj+kO7FBU9zX7 g==; X-CSE-ConnectionGUID: 0zcBOrICS8GqHwtrvjys3Q== X-CSE-MsgGUID: AnejP5ajTqO2rhAbpA3tYw== X-IronPort-AV: E=McAfee;i="6800,10657,11527"; a="69023370" X-IronPort-AV: E=Sophos;i="6.17,302,1747724400"; d="scan'208";a="69023370" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Aug 2025 22:44:42 -0700 X-CSE-ConnectionGUID: mUm1pFzNTeqQ5B79w0AnfA== X-CSE-MsgGUID: DwpOzdFPQAGfBQa0tBk2QQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.17,302,1747724400"; d="scan'208";a="167223923" Received: from tassilo.jf.intel.com (HELO tassilo) ([10.54.38.190]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Aug 2025 22:44:43 -0700 Date: Tue, 19 Aug 2025 22:44:41 -0700 From: Andi Kleen To: "Mi, Dapeng" Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Ian Rogers , Adrian Hunter , Alexander Shishkin , Kan Liang , Eranian Stephane , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Dapeng Mi , kernel test robot Subject: Re: [Patch v3 3/7] perf/x86: Check if cpuc->events[*] pointer exists before accessing it Message-ID: References: <20250820023032.17128-1-dapeng1.mi@linux.intel.com> <20250820023032.17128-4-dapeng1.mi@linux.intel.com> 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: > Andi, I didn't fully get the exact meaning about the "log" here. When > throttle is triggered, perf_event_throttle() has already called > perf_log_throttle() to log the throttle event although only for the group > leader. Is it enough? Throttle normally doesn't involve data loss, just less samples. But this is data loss, so it's an overflow. -Andi