From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) (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 CB7A71DF970; Wed, 11 Jun 2025 18:53:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749668010; cv=none; b=A8Ts9zllufVgEAFPgxE3mImhCnZTzRLnyGAStQ7FNZfFa/QjuSzMtZex10FoAj683lQPHEO+cBJ3YWHfzOFOlW60EdpnHdJc1p8zqki2ooUuaXa3sVD9av8+/N09yP4bIPvLCHhA/0k753Cs+qRxqYOa39mIZN9EGngvH41clCk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749668010; c=relaxed/simple; bh=K7MhSkF7SxF7ufllQxHFuRdtuvoj4RRa+0bILj4Fgf8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=j5MKqOvzPGRTxsU1asQI1nec05tsUxfZtsUpbdzUAYv1a/rnbp8Bk3JRj+ivWML19Ww8GY+IZGh2y18NCRnPO/ujRouOxEqxNoQa7aoMyMKy5WsHX6GBvQMbhw45MBXuR/JK+x78G2oKiCLl6cVda8ADBpvDrkR96nc+vc3gZk8= 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=Sa+BkxyI; arc=none smtp.client-ip=192.198.163.14 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="Sa+BkxyI" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1749668009; x=1781204009; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=K7MhSkF7SxF7ufllQxHFuRdtuvoj4RRa+0bILj4Fgf8=; b=Sa+BkxyIvQkkGCI+pgKMS9PvZONrPcaDS8blFLHGICa7XgORdRGrFVcK 4keDZZualHmV56SIuUQD6DpIXr9rrVrvfhcj5sYIL3H6qcA9C/6nlBD6B 9E3MyCXMQW/p26zajQai9vPSo6oB7rxmBRZo22tOGRpA4xa9kF0FURKqv QOLRMJt2knj4NT8r3eFBFu9LxY1kgBWQKXU2CoIwY0wxJh66SdfmZlLcQ IB8RsoZJINpYgK6tcSMCjSGDSWJnlyvnjlH7w2Pe6qskaYnSR26mgJWKg CQ2RJ2rz1u/33HzWHCBE+SFGgmvqe1Xg3RVDfgZQ/hsaaKyuXRehlHUe7 w==; X-CSE-ConnectionGUID: B8R67JbYS+yruamsA6hhnA== X-CSE-MsgGUID: elz9/HaJSU2lP4g7cH/RRg== X-IronPort-AV: E=McAfee;i="6800,10657,11461"; a="51922699" X-IronPort-AV: E=Sophos;i="6.16,228,1744095600"; d="scan'208";a="51922699" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jun 2025 11:53:26 -0700 X-CSE-ConnectionGUID: PYxOXzNfTgqTZiUkuPjeCQ== X-CSE-MsgGUID: hRtrYbu6RxGkWIfQ0FGYLA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,228,1744095600"; d="scan'208";a="147159241" Received: from linux.intel.com ([10.54.29.200]) by orviesa006.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jun 2025 11:53:26 -0700 Received: from [10.246.136.52] (kliang2-mobl1.ccr.corp.intel.com [10.246.136.52]) (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 9A45C20B5736; Wed, 11 Jun 2025 11:53:24 -0700 (PDT) Message-ID: Date: Wed, 11 Jun 2025 14:53:23 -0400 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: [perf] crashing bug in icl_update_topdown_event To: Vince Weaver Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter References: <352f0709-f026-cd45-e60c-60dfd97f73f3@maine.edu> <080706b6-ed21-540d-dfae-ae27d130d796@maine.edu> Content-Language: en-US From: "Liang, Kan" In-Reply-To: <080706b6-ed21-540d-dfae-ae27d130d796@maine.edu> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2025-06-11 10:57 a.m., Vince Weaver wrote: > On Wed, 11 Jun 2025, Vince Weaver wrote: > >> Oops: general protection fault, maybe for address 0xffff89aeceab400: 0000 >> CPU: 23 UID: 0 PID: 0 Comm: swapper/23 >> Tainted: [W]=WARN >> Hardware name: Dell Inc. Precision 9660/0VJ762 >> RIP: 0010:native_read_pmc+0x7/0x40 >> Code: cc e8 8d a9 01 00 48 89 03 5b cd cc cc cc cc 0f 1f ... >> RSP: 000:fffb03100273de8 EFLAGS: 00010046 > > one additional note that's probably relevant, this is on a hybrid CPU > machine, so CPUs 16-23 are atom cores that don't support topdown. > > So the crash is probably because for whatever reason the kernel is trying > to read topdown events on an unsupported core and triggering a GPF. > It seems an regression from the f9bdf1f95339 ("perf/x86/intel: Avoid disable PMU if !cpuc->enabled in sample read"). The commit merged the intel_pmu_auto_reload_read() and intel_pmu_read_topdown_event(). It's possible that a PEBS event 0x0400 runs on a ATOM CPU. So the PERF_X86_EVENT_AUTO_RELOAD is set for the event. The is_topdown_event() also returns true. Does the below patch help? It checks the PERF_X86_EVENT_TOPDOWN flag as well before invoking the topdown functions. diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index c60b6f199f51..67f80a683234 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -2826,7 +2826,8 @@ static void intel_pmu_read_event(struct perf_event *event) * If the PEBS counters snapshotting is enabled, * the topdown event is available in PEBS records. */ - if (is_topdown_event(event) && !is_pebs_counter_event_group(event)) + if (is_topdown_count(event) && is_topdown_event(event) && + !is_pebs_counter_event_group(event)) static_call(intel_pmu_update_topdown_event)(event, NULL); else intel_pmu_drain_pebs_buffer(); Thanks, Kan