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 037991C6FF4; Thu, 6 Feb 2025 13:49:18 +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=1738849764; cv=none; b=Sp+6Pynkj4DIs50CHGBklejF43pOVe2dsMDK62Ik7BcFDcY86Ky2461bTCm0n1+dMuYx8cSad/ieYHxR9/lbTispaHmd5F9tZ9z0karuvzyOeWOjrI63acEgFP3ZxPv4vVJll5y65FW9KpWvuUoDET/EZbBKbsAesucjeoZrFc0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738849764; c=relaxed/simple; bh=Y3vfxgqWOZEe0Hd/ewi+GadlPXvOgCMGGR4Qn8Wddt8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=m2GPmPQhlYcWi5Gm8apGI4swJcg81Nqi39S7Rm+DuOo+NiVw+TN/zyewwdVo01xep0dvMezvDkyOCR9jD7B5TiwO9ZrvMmEzKKyDpCfMrmqbTDHaXEK3rrmTtokvkxIYzMdeLA0QtHFZWwiyJw1bqzk2/n+6ewtwmGfQoN2MLiQ= 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=XR64Ar5+; 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="XR64Ar5+" 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=Y3vfxgqWOZEe0Hd/ewi+GadlPXvOgCMGGR4Qn8Wddt8=; b=XR64Ar5+6ywuSr/mxmKOGYU1hk CE42fj6bIFgcGYiv61/sT4VfvuTtu+6cwaWwZqUntvKFp87sKx5a6x0daN3QhCHOp5/MTnQZQmx1L 2vEWVTTmPajAydU4sYQSzvwh98kkYWpmg1jst42chKqHf6Sn/6pgeGN543PdGPa6KHx1MGHHq/Avd 8267K7LR7JZn6xmi+uFz8sqWaC3l/3tvGwAQVaBqmUzgUJGqTQzQNzBIjbui7EielG+zTOcyefl7Z 55PtNg4aBDKMKyNWH4RE/sV2arFMjyH/PHla5UHwBtBZqoeqa/qKAA+192e0USeQ/RvlDGUsO3DD7 0D/vsLag==; 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 4.98 #2 (Red Hat Linux)) id 1tg2FZ-0000000GxJY-2XaM; Thu, 06 Feb 2025 13:49:01 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 9F58C300318; Thu, 6 Feb 2025 14:48:59 +0100 (CET) Date: Thu, 6 Feb 2025 14:48:59 +0100 From: Peter Zijlstra To: Sebastian Andrzej Siewior Cc: Steven Rostedt , Joel Fernandes , Prakash Sangappa , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Thomas Gleixner , Ankur Arora , Linus Torvalds , linux-mm@kvack.org, x86@kernel.org, Andrew Morton , luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, willy@infradead.org, mgorman@suse.de, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, Boris Ostrovsky , Konrad Wilk , jgross@suse.com, Andrew.Cooper3@citrix.com, Vineeth Pillai , Suleiman Souhlal , Ingo Molnar , Mathieu Desnoyers , Clark Williams , daniel.wagner@suse.com, Joseph Salisbury , broonie@gmail.com Subject: Re: [RFC][PATCH 1/2] sched: Extended scheduler time slice Message-ID: <20250206134859.GP7145@noisy.programming.kicks-ass.net> References: <9DA1FAE6-A008-4785-BDF9-541457E29807@joelfernandes.org> <20250204220418.35949317@gandalf.local.home> <20250205081635.397eacb0@gandalf.local.home> <20250206083039.0916ad24@gandalf.local.home> <20250206134408.lD_POjuG@linutronix.de> Precedence: bulk X-Mailing-List: linux-trace-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: <20250206134408.lD_POjuG@linutronix.de> On Thu, Feb 06, 2025 at 02:44:08PM +0100, Sebastian Andrzej Siewior wrote: > SCHED_OTHER vs SCHED_OTHER after all. But please don't delay a wakeup of > SCHED_FIFO/ RR/ DL because of this LAZY hint. Thing will get delayed if interrupts are disabled or kernel has preemption disabled too. So as long as we ensure hint crap is of equal order, nothing cares if you do. If you can't tell the difference between task does hint crap in userspace and task is in the middle of syscall, you can't tell the difference.