From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (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 BA9F332D44B; Wed, 14 Jan 2026 05:19:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768368007; cv=none; b=BEIXqkSDWnSKZHnGw8sk6F4/zwxFawN4Hg9XCCvlzjRfRfk9Ix0ScMY1HcmpLKYhkcc8g2B2dLMdIKVVMFyQprqK+zUTlSQtI6plxrEvig2ofuTz28E3s03gZdl3wIvLpZB4Vdz1E3Dc97roSH5cuLvEubJAmNjS4o4pYKLEDtY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768368007; c=relaxed/simple; bh=+sHfezcMA4HcbHZoQMs4d3VkAepOHntKWbJUqg1hupw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=CCC+udyu2FBzCaP3GX7qoZ9Iuq2psA2Qa/SXr8WlQh6XkjMPcbj6YtyEMnXOtb88/UlYMQM0VWLQ0YgTITanP5rXWD2YefUDg6JaSm2oQY07ZMa0UXcIADh69AFcEIC8iHE9yBd9jGW9Pry8rSDJNzhW8CXFQ5DkthfmRoUndEA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=DpxGLkLZ; arc=none smtp.client-ip=192.198.163.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass 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="DpxGLkLZ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1768367998; x=1799903998; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=+sHfezcMA4HcbHZoQMs4d3VkAepOHntKWbJUqg1hupw=; b=DpxGLkLZ2o7WsC/kt5u+s4x6a4PgeHO1PWqBt64J+QN3PPd7U9C1IUyH VVl7N8y3bRaT36s3+ECpJErohIhRTpdXrZ65UrLBs9hd0p/UXaQq9BV5H opnueofNg0wiSk7nQ9zpUgOjrhviFqbjw0Qxph8UtTYfLLPs/DC8CMf91 JJOBQrcFYiUefHaUEAmPSkl65bvC77XVNQcZ7cK4XkIyg4Z0GFhWtKbGe EvqjRpRTQByBSm1b5qjY1Gi5XSKoGO7sALqd00wVh6Y7i9x6hsnludSCY b2CZny/0ym+AwnAUNZ5p6TfshjxHvGzzSFZGPCeRK0BHLgmEMDzgjAWkd A==; X-CSE-ConnectionGUID: vr5inedCShy/tbJgnjvQcw== X-CSE-MsgGUID: cDPT+NK/TomYnenHc5CApg== X-IronPort-AV: E=McAfee;i="6800,10657,11670"; a="95136172" X-IronPort-AV: E=Sophos;i="6.21,224,1763452800"; d="scan'208";a="95136172" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jan 2026 21:19:51 -0800 X-CSE-ConnectionGUID: XcWO3ktiTra2KGbD59At1w== X-CSE-MsgGUID: ivPiugF+SWeVsxKCskP41A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,224,1763452800"; d="scan'208";a="204474163" Received: from unknown (HELO [10.238.4.29]) ([10.238.4.29]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jan 2026 21:19:48 -0800 Message-ID: <54ac8a9e-e846-42eb-b09e-76e781a4375f@linux.intel.com> Date: Wed, 14 Jan 2026 13:19:46 +0800 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: [PATCH V2 2/2] perf/x86/intel/uncore: Fix die ID init and look up bugs To: Zide Chen , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Ian Rogers , Adrian Hunter , Alexander Shishkin , Andi Kleen , Eranian Stephane Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Xudong Hao , Falcon Thomas , Steve Wahl References: <20260113205650.5201-1-zide.chen@intel.com> <20260113205650.5201-2-zide.chen@intel.com> Content-Language: en-US From: "Mi, Dapeng" In-Reply-To: <20260113205650.5201-2-zide.chen@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 1/14/2026 4:56 AM, Zide Chen wrote: > In snbep_pci2phy_map_init(), in the nr_node_ids > 8 path, > uncore_device_to_die() may return -1 when all CPUs associated > with the UBOX device are offline. > > Remove the WARN_ON_ONCE(die_id == -1) check for two reasons: > > - The current code breaks out of the loop. This is incorrect because > pci_get_device() does not guarantee iteration in domain or bus order, > so additional UBOX devices may be skipped during the scan. > > - Returning -EINVAL is incorrect, since marking offline buses with > die_id == -1 is expected and should not be treated as an error. > > Separately, when NUMA is disabled on a NUMA-capable platform, > pcibus_to_node() returns NUMA_NO_NODE, causing uncore_device_to_die() > to return -1 for all PCI devices. As a result, > spr_update_device_location(), used on Intel SPR and EMR, ignores the > corresponding PMON units and does not add them to the RB tree. > > Fix this by using uncore_pcibus_to_dieid(), which retrieves topology > from the UBOX GIDNIDMAP register and works regardless of whether NUMA > is enabled in Linux. This requires snbep_pci2phy_map_init() to be > added in spr_uncore_pci_init(). > > Keep uncore_device_to_die() only for the nr_node_ids > 8 case, where > NUMA is expected to be enabled. > > Fixes: 9a7832ce3d92 ("perf/x86/intel/uncore: With > 8 nodes, get pci bus die id from NUMA info") > Fixes: 65248a9a9ee1 ("perf/x86/uncore: Add a quirk for UPI on SPR") > Tested-by: Steve Wahl > Signed-off-by: Zide Chen > --- > V2: > - Fix the commit message to note that spr_update_device_location() is > used by EMR, not GNR. > - Rewrite the commit message for clarity. > - Add a Tested-by tag. > > arch/x86/events/intel/uncore.c | 1 + > arch/x86/events/intel/uncore_snbep.c | 13 ++++++------- > 2 files changed, 7 insertions(+), 7 deletions(-) > > diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c > index c126a29ab729..c721042be629 100644 > --- a/arch/x86/events/intel/uncore.c > +++ b/arch/x86/events/intel/uncore.c > @@ -67,6 +67,7 @@ int uncore_die_to_segment(int die) > return bus ? pci_domain_nr(bus) : -EINVAL; > } > > +/* Note: This API can only be used when NUMA information is available. */ > int uncore_device_to_die(struct pci_dev *dev) Not everyone could look at the comment and follow the rule. Could we add a WARN_ON in this function and WARN the users if it's not used appropriately?  Others look good to me. > { > int node = pcibus_to_node(dev->bus); > diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c > index 7ca0429c4004..52dec34d18c4 100644 > --- a/arch/x86/events/intel/uncore_snbep.c > +++ b/arch/x86/events/intel/uncore_snbep.c > @@ -1459,13 +1459,7 @@ static int snbep_pci2phy_map_init(int devid, int nodeid_loc, int idmap_loc, bool > } > > map->pbus_to_dieid[bus] = die_id = uncore_device_to_die(ubox_dev); > - > raw_spin_unlock(&pci2phy_map_lock); > - > - if (WARN_ON_ONCE(die_id == -1)) { > - err = -EINVAL; > - break; > - } > } > } > > @@ -6420,7 +6414,7 @@ static void spr_update_device_location(int type_id) > > while ((dev = pci_get_device(PCI_VENDOR_ID_INTEL, device, dev)) != NULL) { > > - die = uncore_device_to_die(dev); > + die = uncore_pcibus_to_dieid(dev->bus); > if (die < 0) > continue; > > @@ -6444,6 +6438,11 @@ static void spr_update_device_location(int type_id) > > int spr_uncore_pci_init(void) > { > + int ret = snbep_pci2phy_map_init(0x3250, SKX_CPUNODEID, SKX_GIDNIDMAP, true); > + > + if (ret) > + return ret; > + > /* > * The discovery table of UPI on some SPR variant is broken, > * which impacts the detection of both UPI and M3UPI uncore PMON.