From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 BDED54CDF9; Fri, 31 May 2024 06:30:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717137022; cv=none; b=ZBNXcAnrH7oOS6mZxmbSKpPgY/uLauVajn1tutRet4mqTBIP4ZCCQIh7O81eIAhyGfTZNAL3DChj4fa6yex6bM3yyELO+V5753hzTlBbF3V7OXulGYv92xY1SfA6pZaK7XE3cmsFN8HpQJnyJgUxSDxDnWbOYDU2sN//1T76fbM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717137022; c=relaxed/simple; bh=ryUzeilFSwy47t1FN5S64noxvyK7l66pL9dkJAS2C6s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Cn6tmxHn4LLXgrM/wPFLubzdwvn7rKVUjbMwCItLZhgEeqQkIeJSJW4p+5FFTz8Va4dvhrJNH4Ya2bvbNoQPKaVjNxNr9K2fgbn2UYA9CinuMsL4MuWHuHB6kVFNoJjtPrcqIPtx+KxOpR1IYf8Fd8JU3c7akhoxvZGGsKRR+0Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=QFoB69CH; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=wjDiGFYZ; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="QFoB69CH"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="wjDiGFYZ" Date: Fri, 31 May 2024 08:30:16 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1717137018; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=K0QKmm22JdPzh0GWkCWU77DhQui4Y/61huUJNDliaZA=; b=QFoB69CHRFvRO1Fso0pUfBNcwKfvV+h0+FJ/JubW7z2q2efjpJH6b8WXySQFplvr1+uXPZ KLbaZDksbyDfeWdtuooMyEMWp2ZoG1Uk7JhevAk1v/dMmfGLQ9hpLraPoG2PxVOz3zv49k x2CDiEMw2/V/a4e3tSwnS2ueF1V8p9oolXLmNYaG04PACNgDw2vxMaBZrDUbJv1i6YW7RG tg6VtHYT2cTLxQicta5t7yKAAsTuCWRA6rUmFrJfxOR9tsinUBUOzKeatteAwEd58UKcAO CvkGDyB+LajttHbABral2JxJId1Skikf1EwZDGXGZhhxn6JKsXDxr1bKpcvtbw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1717137018; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=K0QKmm22JdPzh0GWkCWU77DhQui4Y/61huUJNDliaZA=; b=wjDiGFYZOlVuL2w0+5a4ueNxOgXg4POfy35IGj/X1kD63/lhPCtWQRjwR3TImhrfyR/JY7 a3VsRjTwQkRt8gCw== From: Sebastian Andrzej Siewior To: Qais Yousef Cc: Ingo Molnar , Peter Zijlstra , Juri Lelli , Steven Rostedt , Vincent Guittot , Daniel Bristot de Oliveira , Thomas Gleixner , Alexander Viro , Christian Brauner , Andrew Morton , Jens Axboe , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org, Phil Auld Subject: Re: [PATCH v2] sched/rt: Clean up usage of rt_task() Message-ID: <20240531063016.OCMg21Uq@linutronix.de> References: <20240515220536.823145-1-qyousef@layalina.io> <20240521110035.KRIwllGe@linutronix.de> <20240527172650.kieptfl3zhyljkzx@airbuntu> <20240529082912.gPDpgVy3@linutronix.de> <20240529103409.3iiemroaavv5lh2p@airbuntu> <20240529105528.9QBTCqCr@linutronix.de> <20240530111044.d4jegeiueizvdjrg@airbuntu> 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=utf-8 Content-Disposition: inline In-Reply-To: <20240530111044.d4jegeiueizvdjrg@airbuntu> On 2024-05-30 12:10:44 [+0100], Qais Yousef wrote: > > This is not consistent because IMHO the clock setup & slack should be > > handled equally. So I am asking the sched folks for a policy and I am > > leaning towards looking at task-policy in this case instead of prio > > because you shouldn't do anything that can delay. > > Can't we do that based on is_soft/is_hard flag in hrtimer struct when we apply > the slack in hrtimer_set_expires_range_ns() instead? We need to decide on a policy first. You don't want to add overhead on each invocation plus some in-kernel ask for delta. ->is_soft is not a good criteria. Sebastian