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 4DAE447AF5C for ; Tue, 1 Sep 2026 10:29:36 +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=1788258578; cv=none; b=tUh2umK0KPgvLp4Oo8OS+wWHP5EZ4ctd3EoC9a5YhYmubsFZQTfNsmoOfHuolIQajafbkhcv410dfZBYqLua+UduMGhz6XHKqliTau5pDoiipEbAutbmtGoSXti4AJ/x3ibLdYRJn9d4Mo0dEKSoKAc/PLOc5dnHiYcGMnlSohY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788258578; c=relaxed/simple; bh=BuROZHB+oAUqZL/+duKbF7C95KZZYofztqYRf0xFPXg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=i4Im1A7QJvhsSaH5Vi5aLlLi8zWXywa6Bq0bu9cMSfdw8UMLlolzq3EyJOIGabzAWsAn5QhvO7DXfea+d0QPn82hAvLxwhMHTIf52NwLKzjHhdfYHxxVkiP1opuCsZN1C0gRIwr8GVCn4I9sb5tvz32e8CvEA3W/DbRAXQgE5dg= 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=CclhBcNQ; 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=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="CclhBcNQ" 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=PUus9S9MODT/QuFwH6nooYCoD+hdaIxSvabuO+GXl/k=; b=CclhBcNQzW+aMW35635m3dmmAU 2cFyY7FteXJwlQUjc1icaB5jJpLE5ys9V2+Tu7k53qyaIyixvmg/uaYnAtf23/6yjEAoPXfEFWpAd aZRzJK/kqv7lKTKSS6OYdgL6vUUrFBqnp9ydWsBFxDPM40mia1kL7SRCv+OeFB42E1adHOOE0QDsC jhl48QBWzZteHxI89jYEmDs3M0QDoncSX5T914/ia/x1QAxpasclWAvGxv6KXA7fSaHuqssx2IMb6 xFG9APm7JP5pxdAXorXZxmk5nN+9k++VhsMsfFWPQL2hrSuUEhyF/Smit7koRsizy8GzDoX2Lk8wg SOmCyBIQ==; 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 4.99.2 #2 (Red Hat Linux)) id 1x1Ljy-0000000Ar4c-1mv8; Tue, 01 Sep 2026 10:29:18 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 43DED30031E; Tue, 01 Sep 2026 12:29:17 +0200 (CEST) Date: Tue, 1 Sep 2026 12:29:17 +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 14/23] sched/cache: Drop prefer_sibling restriction for llc_balance Message-ID: <20260901102917.GH776954@noisy.programming.kicks-ass.net> References: <20260827122816.756234-1-wujianyong@hygon.cn> <20260827122816.756234-15-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: <20260827122816.756234-15-wujianyong@hygon.cn> On Thu, Aug 27, 2026 at 08:28:07PM +0800, Jianyong Wu wrote: > group_llc_balance performs balancing across LLC and NUMA domains. > The prefer_sibling constraint unnecessarily limits its scope, so remove > this requirement entirely from the branch condition. > > Signed-off-by: Jianyong Wu > --- > kernel/sched/fair.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 584297528a9e..5c35a43e5e38 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -13274,9 +13274,9 @@ static struct sched_group *sched_balance_find_src_group(struct lb_env *env) > * Try to move all excess tasks to a sibling domain of the busiest > * group's child domain. > */ > - if (sds.prefer_sibling && local->group_type == group_has_spare && > - (busiest->group_type == group_llc_balance || > - sibling_imbalance(env, &sds, busiest, local) > 1)) > + if (local->group_type == group_has_spare && > + ((busiest->group_type == group_llc_balance) || (sds.prefer_sibling && > + sibling_imbalance(env, &sds, busiest, local) > 1))) > goto force_balance; Not sure about blanked disable. Maybe only disable when cache aware scheduling is present and enabled?