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 C85F019F127 for ; Mon, 3 Nov 2025 14:14:26 +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=1762179268; cv=none; b=BV9Zo8wr6/GwxOW1UVpwMlUH/OlAoeAGz5qFbv/yiudsMvUh+dwk8MowP2E4sEGT9jFCLkYpVMc1FBfS1WkmyJ+XRHccdvHlZ450ILvefuMEqiZ572KABKR+P/bhDt38G6h9I/B+OeeemhC0MyzOGef69isJxrsgUuXYNwLn3DI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762179268; c=relaxed/simple; bh=JGaArpyjlVW/76SFOKStdpgXS3RCeB+iXVixw2rgAJs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=k2JgWKN7PL91dpsJsQ2fIMLAyCkaUH8pBwQeHM3g6oOoJ8TobK6mcPUOx4XCDYa95et079F6COo1JaMUpP1/KIdLOhMrLEcKpagaGMN/FD1Yfeb51nudDE2d67R1AIR/rm3PO8GeipFY7gHaJwtoPAWUwlmAT3sO/7OVCwPs6D0= 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=chqN+X+9; 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=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="chqN+X+9" 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=cCbR8BW+licPz9CLpgORR1v7fuvmYJ7LlKX3uzYVqLU=; b=chqN+X+9wFGec/93Uq/evRSkyH LuVaBZoV0gcookgG/5Ts/reQLB5EPUV61blyJSzfarcWIhImZQl8BzIUfOFtta+pFG1gDWgCGv084 0FbJZ59cOF5aLJFCqsu3A+suUgfuYaLcrVIz8iu4NNX+/f6dYM45lngFv18WE26xnH/lM9mdEhWuy V6BMqQwF7urix6OiZACoxfCKmc5E/TIMY4hS1TKhpE9zXXXDfM7xuTCI0jH7OgZ6v/XBo7Bq7pqSW Ua4tXlaHLHhixhrROxWGR3uM5kIiX06g7oOBcskHwVEmAn0wTWE3PuOQXcce0XzQuwYDDPLNWhmAI 1B/qFycQ==; 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 4.98.2 #2 (Red Hat Linux)) id 1vFvK8-00000008Ip8-1fNw; Mon, 03 Nov 2025 14:14:21 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 2034E300220; Mon, 03 Nov 2025 15:14:21 +0100 (CET) Date: Mon, 3 Nov 2025 15:14:21 +0100 From: Peter Zijlstra To: Mel Gorman Cc: Ingo Molnar , Juri Lelli , Dietmar Eggemann , Valentin Schneider , Chris Mason , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] sched/fair: Reimplement NEXT_BUDDY to align with EEVDF goals Message-ID: <20251103141421.GW4068168@noisy.programming.kicks-ass.net> References: <20251103110445.3503887-1-mgorman@techsingularity.net> <20251103110445.3503887-3-mgorman@techsingularity.net> <20251103140711.GB3245006@noisy.programming.kicks-ass.net> 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: <20251103140711.GB3245006@noisy.programming.kicks-ass.net> On Mon, Nov 03, 2025 at 03:07:11PM +0100, Peter Zijlstra wrote: > > @@ -8734,7 +8819,7 @@ static void check_preempt_wakeup_fair(struct rq *rq, struct task_struct *p, int > > struct sched_entity *se = &donor->se, *pse = &p->se; > > struct cfs_rq *cfs_rq = task_cfs_rq(donor); > > int cse_is_idle, pse_is_idle; > > - bool do_preempt_short = false; > > + enum preempt_wakeup_action preempt_action = PREEMPT_WAKEUP_NONE; > > I'm thinking NONE is the wrong default That was unfinished, kid interrupted me at an inopportune moment and I lost my train ;-) Anyway, the current code defaults to what will be 'pick'. And I suppose we could make the default depend on WAKEUP_PREEMPT but meh.