From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 594421EB19B for ; Sat, 29 Aug 2026 10:31:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787999486; cv=none; b=P1blH4rRw5vGgHJvc+kJNSYXh1xGfx3bweslnfkVtPog5FR0ADLpPZvwiUWZO8KYNnOiyFZlMVTNQoFJ5qfpF6qvXHvq7jdQl+gByhp+3KCZwYdGlrqXJ7wJxoK9qIE6UGCy4/dafoL/yOhZMHEnez+k/ES/0qjcJmhBmdZyw7I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787999486; c=relaxed/simple; bh=GU59R+u6UssUjS7ovlxbj5DThzjnDTV0xst/OUoyLYo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=e4262RBoOMz0lsbbxxSugDz/GGjiUxG5DjR5dNqSQAExgt2Zr/OEEp1OoY8YuFV2udXNhgB2W9axkbUBymms9dPvBWGh6XIif8fGM15HgPefAGH12eumUamaWxHmJ4ZphJtZ5WtGf8rBL3Y+h/R+2Xqrpdr02WF7gQ1I9qhImxQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=pass smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=amWIdUn2; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=pass 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="amWIdUn2" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=tFeHJnfiLjvT405YufwKNGK1pvbaUZoRSpVuXj3avro=; b=amWIdUn2IrSzxEW/4ieYFSFbQq c4rzA83hgoB+DLp4iZ89dutx/2cbb4Uik5zsjnF38wqKpryyH3awkCkaRlBdx3m8M2h2ZfZI+zvgq JTPNWIM51nMK68U1wmM5+0/15Qa80UAI8GKKcQMMQG9nF/qbfbUsr+CzeQSL1qYtx2l2K33ebGyDh JufbhLS8tALhNOh6PYDkck4iNOWTkrPOPzVwM4fV0jP8Jg1kNSrSGGZE9fqznCyDIxNmBUq4jKWzn L0GXTuBt7fJ3ycBaOkTdJW2DbmDwQknDpqqyw5WCvJqU1QXSeQlpyYuqsk/Ftsro4qgXtyGgioSeG Pxpius6A==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.99.1 #2 (Red Hat Linux)) id 1x0GL1-0000000GLW0-1waY; Sat, 29 Aug 2026 10:31:03 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 5D122300382; Sat, 29 Aug 2026 12:31:02 +0200 (CEST) Date: Sat, 29 Aug 2026 12:31:02 +0200 From: Peter Zijlstra To: Jianyong Wu Cc: Ingo Molnar , Juri Lelli , Vincent Guittot , Chen Yu , Tim Chen , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , Shrikanth Hegde , Phil Auld , Andrew Morton , David Hildenbrand , linux-kernel@vger.kernel.org, linux-mm@kvack.org, jianyong.wu@outlook.com, zhongyuan@hygon.cn, huangsj@hygon.cn, wangfengyu@hygon.cn, yingzhiwei@hygon.cn, justin.he@arm.com Subject: Re: [RFC PATCH v2 01/23] sched/topology: Add llc_to_node() to translate LLC id to NUMA node Message-ID: <20260829103102.GE776954@noisy.programming.kicks-ass.net> References: <20260827122816.756234-1-wujianyong@hygon.cn> <20260827122816.756234-2-wujianyong@hygon.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260827122816.756234-2-wujianyong@hygon.cn> On Thu, Aug 27, 2026 at 08:27:54PM +0800, Jianyong Wu wrote: > +static void rebuild_llc_node_map(int size) > +{ > + int *new_map, *old_map; > + u8 *seen_llc; > + int cpu, llc; > + > + new_map = kcalloc(size, sizeof(int), GFP_KERNEL); > + if (!new_map) > + return; > + seen_llc = kcalloc(size, sizeof(*seen_llc), GFP_KERNEL); > + if (!seen_llc) { > + kfree(new_map); > + return; > + } > + > + /* > + * for_each_possible_cpu() revisits the same LLC non-consecutively > + * under SMT (each node's LLCs are walked once per thread), so > + * dedup by llc id via seen_llc[], not by comparing against the > + * immediately preceding CPU's llc. > + */ > + for_each_possible_cpu(cpu) { > + llc = per_cpu(sd_llc_id, cpu); > + if (llc < 0 || llc >= size || seen_llc[llc]) > + continue; > + seen_llc[llc] = 1; > + new_map[llc] = cpu_to_node(cpu); > + } > + kfree(seen_llc); > + > + old_map = rcu_dereference_protected(llc_to_node_map, true); > + rcu_assign_pointer(llc_to_node_map, new_map); > + synchronize_rcu(); > + kfree(old_map); Could that not be: kfree_rcu_mightsleep(old_map); ?