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 8263141B8CD; Tue, 22 Sep 2026 08:28:39 +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=1790065722; cv=none; b=L1wMoVUwELl3lIi9oUNAB8RlJ+PLd97qqUPYSwElUcH/yCtOEoiHIGSzeenq5zwW6j9IK2iXANVH11FFHttTIHCuvbRhnFSMJ8XzrptDzq6oSNWSMnmrjG29kkFQ+WFe2AiHCBWU1fcBwUZTKTQjK845SrhbVT6DPpBYXo+/dhA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790065722; c=relaxed/simple; bh=fwhAdvPKZuy1xRlwtW09qNbSF4k3c3Djj/nU8NPuwHw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PAmA7uifQgeNaQuOW9Wmpr/7r8Xo5unRiUIL59WPugfn6gnmIglcNu7xEafRaGSFNQm2ojwcJ1h35tTOoADzEeAbaZ04PDEI45X1VCCEUZhYKYXrIVV7PYfwPwtnBnRzb641+wUd/tSzls74fTrJXAeYNVhPU4XkstnJNNTr5jQ= 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=fnkRMEyi; 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="fnkRMEyi" 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=PfubRjl4+hlUE9k++w7dZcQM36qRb14JHyPG4O/PKVA=; b=fnkRMEyiFZRlkoIXIkHmeIfAQF uH9xp+wfoaRJvqEirWJ3TsgoXJOI3rJglOKEVHmzBt61a5A5FoP43o7Gxxx85Bivx6xU4m1tHAvM8 00/fJtdacRFl6NMBEaChV0eGI1T/TJXlQXP7NW1Nf+/wEO0WALYUOqoGUbHXU1QJXGljH/iLsqhJA OTqZYTIpJ/vGzhLofEV5kMQNCSuGT6QctBp+1Gig1qQTPYPEXyuAceMjaud5SunG+xdslWl4NvdAZ hEOR9m8IdmMIbu0YezlYbNHuDge13ClURRR9wehj+c+scya0jTU4tgdXJPBiN51z0Xm+hMfbnA0cK clu60l2w==; 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 1x8vrL-00000007k9n-2SPX; Tue, 22 Sep 2026 08:28:16 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 98F9F300754; Tue, 22 Sep 2026 10:28:14 +0200 (CEST) Date: Tue, 22 Sep 2026 10:28:14 +0200 From: Peter Zijlstra To: "Chen, Yu C" Cc: Tim Chen , Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , Kees Cook , Christian Brauner , Alexander Viro , Jan Kara , Shrikanth Hegde , Qais Yousef , Aaron Lu , Srikar Dronamraju , Vineeth Remanan Pillai , Ricardo Neri-Calderon , Lu Wang , Hyunwoo Kim , Zhan Xusheng , Zhan Xusheng , Yi Lai , "Rafael J . Wysocki" , Greg Kroah-Hartman , Danilo Krummrich , Zenghui Yu , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Kayra Cizmeci , stable@kernel.org Subject: Re: [PATCH v2 1/6] sched/cache: Keep nr_pref_llc_running in the runnable domain Message-ID: <20260922082814.GX4121339@noisy.programming.kicks-ass.net> References: <06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com> <20260922072205.GV4121339@noisy.programming.kicks-ass.net> <65ee9df8-2422-4d1a-80d6-41ac51979da1@intel.com> 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: <65ee9df8-2422-4d1a-80d6-41ac51979da1@intel.com> On Tue, Sep 22, 2026 at 04:25:14PM +0800, Chen, Yu C wrote: > Hi Peter, > > On 9/22/2026 3:22 PM, Peter Zijlstra wrote: > > On Mon, Sep 21, 2026 at 05:37:22PM -0700, Tim Chen wrote: > > > @@ -6395,15 +6429,27 @@ static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq); > > > static void set_delayed(struct sched_entity *se) > > > { > > > - se->sched_delayed = 1; > > > - > > > /* > > > * Delayed se of cfs_rq have no tasks queued on them. > > > * Do not adjust h_nr_runnable since __dequeue_task() > > > * will account it for blocked tasks. > > > + * > > > + * This check can be removed because when flat pick > > > + * patches get merged as only task can get delayed, > > > + * same for clear_delayed(). > > > */ > > > - if (!entity_is_task(se)) > > > + if (!entity_is_task(se)) { > > > + se->sched_delayed = 1; > > > return; > > > + } > > > > This is dead code. In Linus' tree, where this will be applied, this can > > never happen. A possible backport of this fix however will need to take > > care. > > > > Would you prefer that we create a separate patch to remove entity_is_task() > for Linus's tree (so that the current patch can be backported, since > cache-aware > scheduling was merged before flat task-pickup)? Nah, I munged it in with a few changes (I removed that cache-sched.c file) and it seems to build. See queue.git/sched/urgent. I'll queue up a patch for sched/core that removes some of that -- if I don't forget and all that.