From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (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 24B882FA0C7 for ; Tue, 13 Jan 2026 02:37:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768271865; cv=none; b=CrPpyhzgmVXMhmF8Nf40ZsYODLOKl97zSx9nY8n5zNwU1dBWqVY3BkTvKPupoUzNypAJ6aWo6hR+u3fiVKgirsC0oPjKUY3zUbMLjPjwEXWU6nEQMLMbP54pnH9DUvfJsKhu/bUxKf2B3lXEqu2/AAV8DqCE5b8jfdoe0nD5Nlg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768271865; c=relaxed/simple; bh=P11J0AcM6oF9FOoaysKmB3HG3Rhl/L+Llb2tWuntrOU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=p/BSEhqrPPq0lje/R4tddq3BZDTWYJ82rqK9yttiCMhDbxaSdeNeCxwmIk4egNA6MWfH2D4xaJiN5qvamonyciccAu+EaW6FI9LyaejaJBNXOh/UsdllSE2q1RpzX/YF3kLHSoQH2doikSJTyXut7OEWmWkt7pWmvEuln3EISdE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=n8sI6xki; arc=none smtp.client-ip=198.175.65.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="n8sI6xki" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1768271864; x=1799807864; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=P11J0AcM6oF9FOoaysKmB3HG3Rhl/L+Llb2tWuntrOU=; b=n8sI6xkiIpZPv9AQbnN7kUmlUo0qYvU7fNlIagcbcmxu/VpdaGC73KNk NLRNGdNNtyVZJWWoFbcponoST4+i+IvMEdPi1MqoG+SfUS5fUdUR4Gr4+ 2hHRyns4JB2ztJqLvS6p9BzcQLFddsk7a2/JkHnnN6I0izbU5K6hc2Sde qNeWn+Wi/EQiscatW8c3HAmF3TFxkAi+lJr1KtY7sX1yyBixAC8roNUNm 20XlmXL1pWjgzTDDMS4BxFzHBy6+gWmKUhjH9xEDC5SMETNnwtKoFGqCM 6fcTxbMhNnzWWsNUXLbKauW54xhe1TcStP61AFO/aSluM1LDKwH9QLhtt Q==; X-CSE-ConnectionGUID: sr4XMov/Rvile2hjbbqs4Q== X-CSE-MsgGUID: MD73XTe/Tii++ijwPaJq5Q== X-IronPort-AV: E=McAfee;i="6800,10657,11669"; a="69450594" X-IronPort-AV: E=Sophos;i="6.21,222,1763452800"; d="scan'208";a="69450594" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2026 18:37:43 -0800 X-CSE-ConnectionGUID: n75pIn/wQCWtmZnzbsN1gg== X-CSE-MsgGUID: 0xcPuzFkRSi6KABJfmIruQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,222,1763452800"; d="scan'208";a="209089213" Received: from unknown (HELO [10.238.1.186]) ([10.238.1.186]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2026 18:37:42 -0800 Message-ID: Date: Tue, 13 Jan 2026 10:37:39 +0800 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] lib/group_cpus: make group CPU cluster aware To: Andrew Morton , Radu Rendec Cc: Thomas Gleixner , linux-kernel@vger.kernel.org, Tianyou Li , Tim Chen , Dan Liang References: <20251024023038.872616-1-wangyang.guo@intel.com> <20251221111047.597248db9868d278c7786f6b@linux-foundation.org> <20260109144746.95feaf11e4214cc4895d4039@linux-foundation.org> Content-Language: en-US From: "Guo, Wangyang" In-Reply-To: <20260109144746.95feaf11e4214cc4895d4039@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 1/10/2026 6:47 AM, Andrew Morton wrote: > On Fri, 09 Jan 2026 14:13:32 -0500 Radu Rendec wrote: > >>>>> This patch improves IRQ affinity by grouping CPUs by cluster within each >>>>> NUMA domain, ensuring better locality between CPUs and their assigned >>>>> NVMe IRQs. >>>>> >>>>> Reviewed-by: Tianyou Li >>>>> Reviewed-by: Tim Chen >>>>> Tested-by: Dan Liang >>>>> Signed-off-by: Wangyang Guo >>>> >>>> Patch hasn't attracted additional review so I'll queue this version for >>>> some testing in mm.git's mm-nonmm-unstable branch.  I'll add a >>>> note-to-self that a changelog addition is desirable. >>> >>> >>> Thanks a lot for your time and support! Please let me know if you have >>> any further comments or guidance. Any feedback would be appreciated. >> >> With this patch applied, I see a weird issue in a qemu x86_64 vm if I >> start it with a higher number of max CPUs than active CPUs, for example >> `-smp 4,maxcpus=8` on the qemu command line. >> >> What I see is the `while (1)` loop in alloc_cluster_groups() spinning >> forever. Removing the `maxcpus=8` from the qemu command line fixes the >> issue but so does reverting the patch :) > > Great, thanks, I'll drop the patch. > > I have notes here that an updated version is expected anyway. Perhaps > due to planned changelog updates. And perhaps hopes for additional > info regarding the runtime effects of the change. This issue has been fixed and change log also updated as below: https://lore.kernel.org/all/20260113022958.3379650-1-wangyang.guo@intel.com/T/#u BR Wangyang