From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1581F26AC1 for ; Wed, 4 Dec 2024 18:46:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733337996; cv=none; b=UnsA7kRxlpAoEnfABKAweBFMd9uCA5uJMLTpKimK+dDZxnDeyvog/IC4xgmEdLGW39JHbV4IR1LUv1oXV8cfjLKPTIIupp6P8jSK75ns387sVt/KUeNk0orviR6VHMY/123eb3Y9HM65KypKEy2zoh7ceSRRkgyjpZTal2JfX3M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733337996; c=relaxed/simple; bh=vZ+NtrN8opjtOgd3OLYYzi72bFsvsf2aJcbiPfxIkv8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=j3bQTOdrqKn0v9T0qWuGisbL6fveOCoN8oeESPdzZqeqN8w71OpzXkuP+bXpx7mBsrpOFI9+yhBU/6UwsLzUHGivaBrp7dSMs2BkXHKSprK0KEHketG0QX6yewyihl2pkPBgfigQaz/Ng6E7923QfS1TFBRjoMs3ixEFo1TadsA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fFjMxuuS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fFjMxuuS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7AD55C4CECD; Wed, 4 Dec 2024 18:46:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733337994; bh=vZ+NtrN8opjtOgd3OLYYzi72bFsvsf2aJcbiPfxIkv8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fFjMxuuSsDZ09DoxKDn+mAvh9yF5ya4OIi0hEJVT9vCMq8AcXLEv2wBB0yKGqoy8F e96aCr0Vd3xcWb61zikIYvJZ6E74jk5bgf0xeydu7Wa1VHNk6gVwl+pp1C4CCKvqfR Y4setpRF6qiTBFjGzgRWbWZH7vOuYJvehv1EoduBxT/Qz3EDjAszTr1J5tBNFoZdaS RzY4h3xb+wMe3GszYc4jotT/Gq/TzN9ffKBCEkeP8NNvc55czmAvOEePkr8DEsW/K9 rnLEGWYIW5S4vRHR0AM+Y8RO9f59HDxmA84PqkTVUg7uy/NDWMIeB99//GFltI7vIJ b6oLmPsnlLiRQ== Date: Wed, 4 Dec 2024 08:46:33 -1000 From: Tejun Heo To: Changwoo Min Cc: Changwoo Min , void@manifault.com, mingo@redhat.com, peterz@infradead.org, kernel-dev@igalia.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/5] sched_ext: Manage the validity of scx_rq_clock Message-ID: References: <20241203142802.36305-1-changwoo@igalia.com> <20241203142802.36305-3-changwoo@igalia.com> 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: Hello, On Wed, Dec 04, 2024 at 10:42:13AM +0900, Changwoo Min wrote: > I investigated all sched_ext_ops. Besides these two ops, all the > rest are control operations, of which BPF operation should be > relatively simple. On the other hand, ops.running() and > ops.update_idle() are different from the others since a CPU > executes a task or becomes idle, which could be arbitrarily long. > So I think refreshing the clock in those cases would be nice. > Does it make sense to you? Hmm... I'm not really following. Both ops.running() and ops.update_idle() are called during task switches with rq lock held. I don't see why they'd be any different in terms of expected runtime, which should be pretty short, compared to any other rq-locked operations. Thanks. -- tejun