From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) (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 67B7A405F7 for ; Mon, 22 Dec 2025 03:03:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766372592; cv=none; b=RsS0EpQnSAYxaB2LsTvz9ncolQ732wJDUsm7wmlOJD6Kw+QFqp9KgVP+1YmRIvM7xl07qjGI/GK2BMrcnitin8gZ9BMIhve+JcfOyPJ59jFdI5L4c80J5wiFdWEJ5glHeFavexsJbB2mMPytqHwyyoqD9ptUNueNUfNVg+5o07o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766372592; c=relaxed/simple; bh=CZQu32pGEU/dJ9+gcPmL+Wlf5lRQT0extfbIfL2Wdfk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YqKaaXCk/tDoWL8EhNH3Pp4Iz5mTbmLb8y/NcH4p+zJMAoCzNr6nG7TDrT17baurdzLh1pWmY9iJHJys6MsWSlO0ZSXplswV759uCPF1BH2UzvqFqoHNomnP1dsr7q129oz6aHNv34/3TCJezfJMA8+Mcf+2gHOn6gmgorK7QpY= 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=K3K2zQnk; arc=none smtp.client-ip=198.175.65.9 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="K3K2zQnk" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1766372591; x=1797908591; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=CZQu32pGEU/dJ9+gcPmL+Wlf5lRQT0extfbIfL2Wdfk=; b=K3K2zQnk25q4WyWG4XbaxlUX2zqAbPHbkOWODhlcG2ulho7+0WIJ+/gF K6BGMZ+pEld2Yt36VCDxUfPup+w98KODvvRvC5SXbxLrno339qpz8Jkeh jPW8eNZPEu+NhnF0qsRhvsE7xI09S+vLVRbqwYmuCYmS8hg3joxez1CFu +VqTLW8ulVhrl7c0Ob8nHTAgkokwvRS2O/HkAa2fWylVGt68itpbiyo21 67GCqScAk7C3DCpmiz8GG3D8HkdHLAFOyDQlqevmQ5aBUDvO2/+xYgeWV yy/ahSLxQmZA81B5+k8raHcqFwlvy3kn5pJB0vbvE6xlYe33t2RyT/W2J g==; X-CSE-ConnectionGUID: uUa0DeJIT06xfgxAlw8Bbw== X-CSE-MsgGUID: MxRQNCokQy+YFVTjTRZkzA== X-IronPort-AV: E=McAfee;i="6800,10657,11649"; a="90891811" X-IronPort-AV: E=Sophos;i="6.21,167,1763452800"; d="scan'208";a="90891811" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Dec 2025 19:03:10 -0800 X-CSE-ConnectionGUID: 7nITP8UwR/CvYyIX1+12lw== X-CSE-MsgGUID: OxrqpS/VSzuR9qEGP5rWpA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,167,1763452800"; d="scan'208";a="230433946" Received: from unknown (HELO [10.238.3.27]) ([10.238.3.27]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Dec 2025 19:03:07 -0800 Message-ID: Date: Mon, 22 Dec 2025 11:03:05 +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 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> Content-Language: en-US From: "Guo, Wangyang" In-Reply-To: <20251221111047.597248db9868d278c7786f6b@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 12/22/2025 3:10 AM, Andrew Morton wrote: > On Fri, 24 Oct 2025 10:30:38 +0800 Wangyang Guo wrote: > >> As CPU core counts increase, the number of NVMe IRQs may be smaller than >> the total number of CPUs. This forces multiple CPUs to share the same >> IRQ. If the IRQ affinity and the CPU’s cluster do not align, a >> performance penalty can be observed on some platforms. > > It would be helpful to quantify "performance penalty". At least give > readers some approximate understanding of how serious this issue is, > please. > Thanks for your reminder, will update changelog in next version. We see 15%+ performance difference in FIO libaio/randread/bs=8k. >> 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. BR Wangyang