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 1F0631DDA15 for ; Tue, 8 Oct 2024 14:40:59 +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=1728398461; cv=none; b=laKrcoJU8I5IVjgtKa8/j2NvltEeOH1GsjScbokvgwXqtLP3EGnT4J/v6rj+p6s9qiJMuQCmOBotbe1wV46+7HImUxNlMyKqqea2SAmmWw7gaOBJMawdxuODykGe+cj7WuuNyVZ2PAHXjcfzpwSPqnQTLmH2d7BVdCFbPKhH3rI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728398461; c=relaxed/simple; bh=t2oL6Zc4nPX4Z1p19OYK0tVi2LFLXNIyQHCgv6pxgqA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mfcIX0HWeFWlYbgxGQJP6w6oErOk7g0DkXj/Budakd7d2roILQaffydgFyIBOAyxE/lWBb7ASwB2Xp/KvLUaUYrKdzEyzEjZXUjmtBHCdpmbAIKKqyrZmkfDN1WXYYYnSRwh6qfz+HGKj9ylbSDlkeHePWvmZwYrpo2ocXXoVLc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=RqbfCQqA; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (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="RqbfCQqA" 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=bUAt1o+OtYHVtE/msqDP5in/OvzMArEV0Xq62EXzpGo=; b=RqbfCQqA8gzYTR6dzfmCbwT4Qf hCvzGuDZTKi6FkvTIp+r+CVaWryJ/jl9FSiTazFOGjyFYan745rLKFP2KOEVw+YnKCEUFVWljbUGb ZjDm1GM75jo0Yewllo5LqJxmrPCK0lK0/y308zg21ek0pWLgs7bw7ybcdUIrHs0S7ivIjcXCOpe0W mrg4NRnHbj/CyAyiF2cADl4U+DB8oykpdv0N/vVYoptwYeSbDGkhNzaTs3bTr1koDfJKuQcHTt2/0 5r7mWqDssC5mQjV5mW9XH9kCgkW2l8/3v5cqyCkGnqMThQPagJP0WUpPcQtFiRLDAdoZI/T2fIiQj 98BQz3Pg==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1syBOM-00000002X6c-1Qgh; Tue, 08 Oct 2024 14:40:51 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 13C03300599; Tue, 8 Oct 2024 16:40:50 +0200 (CEST) Date: Tue, 8 Oct 2024 16:40:49 +0200 From: Peter Zijlstra To: Thomas Gleixner Cc: bigeasy@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, ankur.a.arora@oracle.com, efault@gmx.de Subject: Re: [PATCH 5/5] sched: Add laziest preempt model Message-ID: <20241008144049.GF14587@noisy.programming.kicks-ass.net> References: <20241007074609.447006177@infradead.org> <20241007075055.671722644@infradead.org> <87ed4qu107.ffs@tglx> 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: <87ed4qu107.ffs@tglx> On Tue, Oct 08, 2024 at 04:23:36PM +0200, Thomas Gleixner wrote: > On Mon, Oct 07 2024 at 09:46, Peter Zijlstra wrote: > > Much like LAZY, except lazier still. It will not promote LAZY to full > > preempt on tick and compete with None for suckage. > > > > (do we really wants this?) > > Just to prove how bad NONE is without cond_resched() ? > > I'm sure we can do without that experiment. There's a reason this is the very last patch :-)