From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (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 20D8B284B58 for ; Thu, 19 Feb 2026 18:17:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771525030; cv=none; b=QoPblKCbWY2IWgkN2+TaPNheZNJTw+fsE+8Y0ZyjqfLIiUmuZ22BtydHFkrTYgyzBAoLyK9IKmmzr7mxeSfEQSMkCSAQiZFZ3wk+Cz8QQuxeHNbFpMyNHP0npfjv/oIFAbOViiPA2DjX7rJ66IqvKeP1n6ZgwO8ZMy0Yf3m4E+A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771525030; c=relaxed/simple; bh=/dyUAkViQEhbMH9TBgNEp2RO5M1P037KtLgiq2KVy7k=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=fH6eWSmPz9xYCX0tHB0gTsrxsVuELvbJ4K/KZ+e6I0IUuw2ccQ/S8kt4RMRBt4SS6J/TRrx6JlYXCwSRyvDVwoxQnBCTKO9vL8cYP6SJirY3+4KhneptV59XP9NLvMM4NstDKSp/KMpSqR4u6gKWwSgcRD7g5dUarcGwRXDvSs0= 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=lz4jluBl; arc=none smtp.client-ip=192.198.163.16 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="lz4jluBl" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1771525029; x=1803061029; h=message-id:subject:from:to:cc:date:in-reply-to: references:content-transfer-encoding:mime-version; bh=/dyUAkViQEhbMH9TBgNEp2RO5M1P037KtLgiq2KVy7k=; b=lz4jluBlNSYK5lqqihJeH7cKXQsE+7fGejy47oG+rp2fCbcCinlhtqFJ 0eiPTwPFfIWpIgtsYS3+9MS5g86l5lCkibE755FpbyD3KExkxXy8j5mnC DZ5NIIXKDSYIUZie6U5Xk0AfxlAfY2PJkZioGZsdF2kPisvYIEXAFYtlM 17/pI6xEAHhB4V9kKhpbmYAsVP4OwDNajCyIl8xCjcnDbS8voi9duJEz1 WYHPMoC6QFGjTQcqQ6A2oJ8ASPuNXqJnDi3cIzU+XapDsZpXOE5XEuicN UXFruheH9HnIU9BJ0SJh/MGEXDu0lOpiOarZbSC0Yyn8JmuzKuTDhVucV Q==; X-CSE-ConnectionGUID: oc7Ww2qVSRuIjM1IrKFVkA== X-CSE-MsgGUID: bQqdyKV+Tw2bof/R51H96w== X-IronPort-AV: E=McAfee;i="6800,10657,11706"; a="60194985" X-IronPort-AV: E=Sophos;i="6.21,300,1763452800"; d="scan'208";a="60194985" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Feb 2026 10:17:08 -0800 X-CSE-ConnectionGUID: ev2QqJd6QqqOt+kbIwofNw== X-CSE-MsgGUID: L3eIVx2uTUGeKq2KT+QaTA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,300,1763452800"; d="scan'208";a="212816589" Received: from unknown (HELO [10.241.243.83]) ([10.241.243.83]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Feb 2026 10:17:07 -0800 Message-ID: Subject: Re: [PATCH v3 04/21] sched/cache: Make LLC id continuous From: Tim Chen To: Peter Zijlstra Cc: Ingo Molnar , K Prateek Nayak , "Gautham R . Shenoy" , Vincent Guittot , Chen Yu , Juri Lelli , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Madadi Vineeth Reddy , Hillf Danton , Shrikanth Hegde , Jianyong Wu , Yangyu Chen , Tingyin Duan , Vern Hao , Vern Hao , Len Brown , Aubrey Li , Zhao Liu , Chen Yu , Adam Li , Aaron Lu , Tim Chen , Josh Don , Gavin Guo , Qais Yousef , Libo Chen , linux-kernel@vger.kernel.org Date: Thu, 19 Feb 2026 10:17:06 -0800 In-Reply-To: <20260219113523.GG1395266@noisy.programming.kicks-ass.net> References: <60a05a3f50d14a7bf3b968f62cca87893c5c552c.1770760558.git.tim.c.chen@linux.intel.com> <20260219113523.GG1395266@noisy.programming.kicks-ass.net> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.1 (3.58.1-1.fc43) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Thu, 2026-02-19 at 12:35 +0100, Peter Zijlstra wrote: > On Tue, Feb 10, 2026 at 02:18:44PM -0800, Tim Chen wrote: > > From: Chen Yu > >=20 > > Introduce an index mapping between CPUs and their LLCs. This provides > > a continuous per LLC index needed for cache-aware load balancing in > > later patches. > >=20 > > The existing per_cpu llc_id usually points to the first CPU of the > > LLC domain, which is sparse and unsuitable as an array index. Using > > llc_id directly would waste memory. > >=20 > > With the new mapping, CPUs in the same LLC share a continuous id: > >=20 > > per_cpu(llc_id, CPU=3D0...15) =3D 0 > > per_cpu(llc_id, CPU=3D16...31) =3D 1 > > per_cpu(llc_id, CPU=3D32...47) =3D 2 > > ... > >=20 > > Once a CPU has been assigned an llc_id, this ID persists even when > > the CPU is taken offline and brought back online, which can facilitate > > the management of the ID. > >=20 > > Co-developed-by: Tim Chen > > Signed-off-by: Tim Chen > > Co-developed-by: K Prateek Nayak > > Signed-off-by: K Prateek Nayak > > Signed-off-by: Chen Yu >=20 > Note that Tim is the one sending this email, so his SOB should be last. > It is also fine to have a SOB occur multiple times in a chain. >=20 > Please double check all these SOB chains, because I think this isn't the > first one that isn't right (possibly the very first patch already has > problems). Sorry about that. Will correct this on the next version. Tim