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 89A684AED7 for ; Fri, 12 Apr 2024 07:43:30 +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=1712907811; cv=none; b=H9BMTXiS0Xf8FvOJygKNECwFhCWkKG3EYBQhoPavwer6+Yp5rGoVUy/ct8jhN5bP60CPDKbGE5F5d7cK0GmqVc0rHb/TdJMmwyszCyJrYua9vQNoy8fEkzbg08jH6inh84ZqsvQFKBNxpbExJLWibElMsyZGALFfBrBHBG/949U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712907811; c=relaxed/simple; bh=StuD/HabmuU7PxPUah/OQP/1NIIFVO5VCeXkpG1dpsY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FdV+nZSYBFapVqt3S1dFNRl/yvSpoam5zyBP2RkfTnOeixaCUta+XxfBy5ZMu0t1OsDMxQJdmyDC7wxlQPDNoxzJ+ARSMHJ4cSbbjcE1ZIir2HleEeN2azdG1B8yGMfTlzsUDJiGRnIg+aXQX52wNQlxd/EelnEpE9L2uPClI70= 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=ZHPJPU+D; arc=none smtp.client-ip=90.155.92.199 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="ZHPJPU+D" 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=1YvrhE8TYy7MSDseUcEX6cz+zJ82RxWENHKzY8nEqT8=; b=ZHPJPU+D5hwpm4wgpiMkbWmAxe zXeC9sXfI+1FJnmhRYSQcLRzNzJM4biKq0RAhRlaWBiTbu7fVxyM62i/DPuAWZ/QapdcdXA13H69b 5CgUBm7Ejn1AeJZHCANVRys0942eAYLDwkZRr5j2FULQtNrk9WDqEtlduc69/83QPIV+RoriSTIRQ a11icLFVn3uMaB36w7E2w9dfiPtrOUhmWSOIVakxOe4fyvcWea1lTxsw7JbE33cJ17IV3dcXJI4ok 7embbdWMXspwSvH7rH0e7bQGxpMI4e3BHjN3f+XmScIEf0+vR5qC1i0YeHWWCM8KX8IKjNJK0o5Uu FaqJ+82g==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1rvBZ6-000000091se-2gk3; Fri, 12 Apr 2024 07:43:17 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 4DD8A3004D5; Fri, 12 Apr 2024 09:43:16 +0200 (CEST) Date: Fri, 12 Apr 2024 09:43:16 +0200 From: Peter Zijlstra To: Daniel Bristot de Oliveira Cc: Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , linux-kernel@vger.kernel.org, Luca Abeni , Tommaso Cucinotta , Thomas Gleixner , Joel Fernandes , Vineeth Pillai , Shuah Khan , Phil Auld , Suleiman Souhlal , Youssef Esmat Subject: Re: [PATCH V6 3/6] sched/fair: Fair server interface Message-ID: <20240412074316.GF30852@noisy.programming.kicks-ass.net> References: <1abba9e7f47ad4a5dfd8b2dfb59aa607983cdce4.1712337227.git.bristot@kernel.org> <20240411144327.GB40213@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: On Thu, Apr 11, 2024 at 05:02:41PM +0200, Daniel Bristot de Oliveira wrote: > On 4/11/24 16:43, Peter Zijlstra wrote: > > The 'defer' thing is dubious though, I don't suppose anybody would ever > > want to actually change that, other than you while poking around at this > > code, right? > > In a setup where all real-time tasks are DL (without fixed-priority tasks (FIFO/RR)) > the defer = 0 makes more sense because the bandwidth is reserved anyways, and the > DL server would have a relatively low prio (long period). Tell me more -- how is it better in that case? I would think it wouldn't matter much.