From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.17]) (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 5A40FEACD; Wed, 20 Aug 2025 03:41:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755661283; cv=none; b=nl6AlhkCUFXGQrxv1YxVgwvh/cr4IYwVhYh/WjfdaGX1gW6SZbL2e6cQrQ6pA6/HCXZqpiSvWyir/SMDVSYsHgxZEWm+WHM7yK57BSyTuIC5/vEnabRYUUty+FlmVP3ax0+iACfPCAdIwOX+OmUL8+eiJfo5pFOMuz7B+WEe+KM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755661283; c=relaxed/simple; bh=BYtBIItxQ8/8NKbDlgKsXdYMcCsN52tFIR92Wi3omMc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=sOS5jFWVmw2moZQwN5nxyzArSc3OcjedkyZZqydYxhpE3USs1XNVsK2uaoZa5V/IhrgK3tCyIO4UPd44LaJXfNFprYsVcZbZemZbzY0OzsG0Ez9jk7swCctNagTJ6Om7EMwsZt/UD65ZOuu/gvOJWK0c/LEIatbOcxjXYBkJ5qw= 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=T7XnulBD; arc=none smtp.client-ip=198.175.65.17 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="T7XnulBD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1755661283; x=1787197283; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=BYtBIItxQ8/8NKbDlgKsXdYMcCsN52tFIR92Wi3omMc=; b=T7XnulBDeQu/mgLI9Ix++XixNJuma0l33vZ1HTfWn9VHTl4PirInO1Z9 g5jOndNIFHyoSl1iTySRkMn8S5B6+SpchSuB2HRmHBFJ4gHPYDADiX1cP N+VBXHp3z/n472/VUsCnYSNLKEgcd2eZ0Z6ATyr0z+iKm1yZPOGNYRKgk +4Jg+LweRZPKcFEhhAqpZDq8s9sS8sWbH4Mj/bxE//oMFEnulYz7rR5QD MCmdtCF9fJQQ0W3w6HhfyWuR467scs5LTX+VMDoxI1bXLxrY6YVnaurz2 /s5V6ZAeTar/cmBhaB2XD3LSRSw5h7NjQhAsEMwFNYB9g1eqvwRA8N3bs g==; X-CSE-ConnectionGUID: iw7eY7PxQX+q1RTsJI7gzg== X-CSE-MsgGUID: fs2+yQOZTcm+7VyofhyBxQ== X-IronPort-AV: E=McAfee;i="6800,10657,11527"; a="57872701" X-IronPort-AV: E=Sophos;i="6.17,302,1747724400"; d="scan'208";a="57872701" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by orvoesa109.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Aug 2025 20:41:22 -0700 X-CSE-ConnectionGUID: SDIcRT6JRzOSnsnCMWbh5A== X-CSE-MsgGUID: aupXOxlORO6M6xh0h/SX5w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.17,302,1747724400"; d="scan'208";a="167240343" Received: from tassilo.jf.intel.com (HELO tassilo) ([10.54.38.190]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Aug 2025 20:41:22 -0700 Date: Tue, 19 Aug 2025 20:41:20 -0700 From: Andi Kleen To: Dapeng Mi 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-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: <20250820023032.17128-4-dapeng1.mi@linux.intel.com> > event = cpuc->events[bit]; > + /* > + * perf_event_overflow() called by below __intel_pmu_pebs_last_event() > + * could trigger interrupt throttle and clear all event pointers of the > + * group in cpuc->events[] to NULL. So need to re-check if cpuc->events[*] > + * is NULL, if so it indicates the event has been throttled (stopped) and > + * the corresponding last PEBS records have been processed in stopping > + * event, don't need to process it again. > + */ > + if (!event) > + continue; Then we silently ignore the overflow. Would be better to log at least an overflow packet or something like that. -Andi