From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199])
	(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 2849934A3D8
	for <linux-kernel@vger.kernel.org>; Thu, 19 Feb 2026 15:52:17 +0000 (UTC)
Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199
ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;
	t=1771516338; cv=none; b=huuTslrz8brkyUjlr68EOZOTZoRVXU2k2/DXRfa2DLax1ynXgoDe0Xg1kq/t6Evp8gmn/P4rW6sRBV8Oo1PHRFNnZ/yIND3azq5g6jDgFfP5KYHfwa9clzanl46XaNPOWCadR1SJF53nnNVejlcPNjAgmUzqubNGd2yGpcTHt+k=
ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org;
	s=arc-20240116; t=1771516338; c=relaxed/simple;
	bh=8Jj9qRuqnZtg3FELE+PTsgcItl3unmHo/MC2Sy4X228=;
	h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version:
	 Content-Type:Content-Disposition:In-Reply-To; b=agYda5ZqXfYIHf75+jyLgyIDt1iQf0OA1/cwcN+Oo3Hv5pHOUP5HTkBjt/a65sHZEidv/hsW5q/TNgE7bgWkJ/3FsMF8UnJY2teZPdnGsAFId0XhGVFNYMkwnglp1y7O9gPwHjf+/JHot+Dptvl6Hu529e1IafRx6L3yP8cJRW0=
ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=gRhFkIEr; arc=none smtp.client-ip=90.155.92.199
Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org
Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org
Authentication-Results: smtp.subspace.kernel.org;
	dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="gRhFkIEr"
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;
	d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version:
	References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:
	Content-Transfer-Encoding:Content-ID:Content-Description;
	bh=BwtBQ73wnpxpyeL7TxLF/zJ4P/iOhJWSlRj0TLgyQKc=; b=gRhFkIEra7dyOXb4EVeNa6dL/M
	LXqgVdMbR+nmrQTcyqr82Bt/X+xY1Fi+HLoU3jqj8vyHSfodlFRPMUBmWm7OXLSbKpqoovv7opmdR
	2tlSHep0oKGP8lzUFEaxtu9wn1GOKZMr223DETVRD4rMvS1+GtN/I98XG3eqafyjb0lpWLovPWhK2
	eTiO54EN/K7EIV83reQhAtLbctk6V6Fj4ApPk5iTNEDOUXArZQmsgt26jml6am+2wi8g8P9JwxZzm
	lhYNhIK7KV29vUkBiCxdzCv4kdjZUlpV847RY/YxjAFnnYFZoINQ4m1OJh0cKOaM1+HwuOhYm7bzF
	q5p8UPvg==;
Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net)
	by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux))
	id 1vt6Je-00000001VEV-39MA;
	Thu, 19 Feb 2026 15:51:47 +0000
Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000)
	id 8B822300B40; Thu, 19 Feb 2026 16:51:45 +0100 (CET)
Date: Thu, 19 Feb 2026 16:51:45 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>,
	"Chen, Yu C" <yu.c.chen@intel.com>,
	Juri Lelli <juri.lelli@redhat.com>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
	Valentin Schneider <vschneid@redhat.com>,
	Madadi Vineeth Reddy <vineethr@linux.ibm.com>,
	Hillf Danton <hdanton@sina.com>,
	Shrikanth Hegde <sshegde@linux.ibm.com>,
	Jianyong Wu <jianyong.wu@outlook.com>,
	Yangyu Chen <cyy@cyyself.name>,
	Tingyin Duan <tingyin.duan@gmail.com>,
	Vern Hao <vernhao@tencent.com>, Vern Hao <haoxing990@gmail.com>,
	Len Brown <len.brown@intel.com>, Aubrey Li <aubrey.li@intel.com>,
	Zhao Liu <zhao1.liu@intel.com>, Chen Yu <yu.chen.surf@gmail.com>,
	Adam Li <adamli@os.amperecomputing.com>,
	Aaron Lu <ziqianlu@bytedance.com>, Tim Chen <tim.c.chen@intel.com>,
	Josh Don <joshdon@google.com>, Gavin Guo <gavinguo@igalia.com>,
	Qais Yousef <qyousef@layalina.io>,
	Libo Chen <libchen@purestorage.com>, linux-kernel@vger.kernel.org,
	"Gautham R . Shenoy" <gautham.shenoy@amd.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH v3 04/21] sched/cache: Make LLC id continuous
Message-ID: <20260219155145.GK1395266@noisy.programming.kicks-ass.net>
References: <60a05a3f50d14a7bf3b968f62cca87893c5c552c.1770760558.git.tim.c.chen@linux.intel.com>
 <79755f7d-cc68-4189-b6d8-850378e54017@amd.com>
 <95923e36-4117-4209-97aa-a92b60f2bd49@intel.com>
 <6a73ac0d-1fc9-49a7-87a2-65951ab2c844@amd.com>
 <8df218ecf39015830856c7b1053a0f777cc1ea42.camel@linux.intel.com>
 <579c9039-cd66-41c3-8a72-e73d6f836ee8@amd.com>
 <f891e7d3-98d1-4590-9335-f12225407fd6@intel.com>
 <be8d4efa-e29a-4463-a7fc-50320aebf1cd@amd.com>
 <acc7a5c96e8235bf11af640798ce1b60bcaa8196.camel@linux.intel.com>
 <3de1e4ff-2da5-4a58-a4ea-03accf4b7572@amd.com>
Precedence: bulk
X-Mailing-List: linux-kernel@vger.kernel.org
List-Id: <linux-kernel.vger.kernel.org>
List-Subscribe: <mailto:linux-kernel+subscribe@vger.kernel.org>
List-Unsubscribe: <mailto:linux-kernel+unsubscribe@vger.kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <3de1e4ff-2da5-4a58-a4ea-03accf4b7572@amd.com>

On Thu, Feb 19, 2026 at 11:42:58AM +0530, K Prateek Nayak wrote:

> I don't think we need to special case this out since:
> 
>     for_each_cpu(j, cpu_coregroup_mask(i)) {
>         ...
>     }
> 
> would bail out if no CPU is set (also CPU "i" would definitely be
> set on it since it must be online) and the "if" after the loop will
> see "lid" as "-1" and DTRT.

So tying lid to coregroup_mask, rather than sched_domains might make
sense. It avoids that partitions nonsense.