From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f177.google.com (mail-il1-f177.google.com [209.85.166.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 40D4C189532 for ; Thu, 26 Sep 2024 22:07:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727388446; cv=none; b=D7eUSMuGRJ7zX0RFuIrt6Q3za+6PXrEWJ1vD0QQzNNgkeYOTQylnA0+Xd6zmHGpiSRJIlpzoDh3DjohWAVsqqv111cCoh3sOinbrgPxak5o5Mb+mb1zn6xbC5UCajm21mPNeEKY6tIoaXV5CyCu4VJKy2IUe3B3vD4LXzSc5zKI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727388446; c=relaxed/simple; bh=9P2wSIHgEWRsKAiTBVfIi4WWLw5alWynd5o/WKm8Fys=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tZTejk0ZsDKALpQMljjqbTkOpFpFc0sxFaSvCge9J0y+BtMvIiPb7xFOpS+klFexxXqD0O4lfKQijxW02tOCfVK/386mcjP7UfprX4H+GDqZb3BmCv6PNW9vi5Lyjpvge+XmQw9HV9TGG3LLa2AymGxxrOFy7RVOJ+QIe7fuGD0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=manifault.com; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.166.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=manifault.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-il1-f177.google.com with SMTP id e9e14a558f8ab-3a0c8c40560so5977345ab.2 for ; Thu, 26 Sep 2024 15:07:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1727388444; x=1727993244; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=9P2wSIHgEWRsKAiTBVfIi4WWLw5alWynd5o/WKm8Fys=; b=sOEOtsqoG5u6QbwaoMdL6QdqxrUdI6BW1pwXI/cokMNn6FvZv3p1BExm+fQxtvebEj U3vqNHUA/qqIpB1GicswA/B2x8s6aKQLv3Hg0kZ73SyEO/Yq0Kyd8veRvQOw6Osy/gxV z6QIBVp5rnHoo24y1ZdSLz9KcGcgozDXMVKeRgix0YhtmVCBQXJ7INMWrrrwgU9fwr4y gO8MhygXksLzbfMQUifKoBRBUTlY6aNPJIXujIblkA0abfTNJiZylGrHwTgnCfga0stO XpXxqRUIdzTSG2QNt6KUsUQkk91yHTBnckApw6KmHvG25Ts/oL0J/TnksbY6vqeWQk9F uG0w== X-Forwarded-Encrypted: i=1; AJvYcCUDElPp4qep9tBIrK7b3QM10yJIKyTiqze1YeYORH5jChmnve51DijzmaA7bfzPV0DC4x7NmimUnCzkpQw=@vger.kernel.org X-Gm-Message-State: AOJu0Yz1KafWRkzXgUwWuKu2Jxm2cgo8V/qaFHh9mgX+DipFozl2OjzY k4TYFcNoPmvIhuPCjzK06reMmtfmp2rB42EawOcjR62XJiSe5g3vy1PTUfUk X-Google-Smtp-Source: AGHT+IHw6F/mYFCkzcxNHw4Y517yZdwrjmL3qESs+Xf4Af3jsBOlSe9VNPQdJsXGKHyAteo4/cW0yQ== X-Received: by 2002:a92:c56f:0:b0:3a0:9a32:dedc with SMTP id e9e14a558f8ab-3a3451703b8mr9805615ab.6.1727388444196; Thu, 26 Sep 2024 15:07:24 -0700 (PDT) Received: from maniforge (c-76-141-129-107.hsd1.il.comcast.net. [76.141.129.107]) by smtp.gmail.com with ESMTPSA id 8926c6da1cb9f-4d8888d854esm155683173.124.2024.09.26.15.07.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 Sep 2024 15:07:23 -0700 (PDT) Date: Thu, 26 Sep 2024 17:07:21 -0500 From: David Vernet To: Tejun Heo Cc: kernel-team@meta.com, linux-kernel@vger.kernel.org, sched-ext@meta.com Subject: Re: [PATCH 5/5] sched_ext: Use shorter slice while bypassing Message-ID: <20240926220721.GG26346@maniforge> References: <20240925000622.1972325-1-tj@kernel.org> <20240925000622.1972325-6-tj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="UHQ/JnmahpbiWvxX" Content-Disposition: inline In-Reply-To: <20240925000622.1972325-6-tj@kernel.org> User-Agent: Mutt/2.2.13 (00d56288) (2024-03-09) --UHQ/JnmahpbiWvxX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Sep 24, 2024 at 02:06:07PM -1000, Tejun Heo wrote: Hi Tejun, > While bypassing, tasks are scheduled in FIFO order which favors tasks that > hog CPUs. This can slow down e.g. unloading of the BPF scheduler. While > bypassing, guaranteeing timely forward progress is the main goal. There's no > point in giving long slices. Shorten the time slice used while bypassing > from 20ms to 5ms. My vote would be to just update SCX_SLICE_DFL to be 5ms, but this is fine as well if you'd prefer to leave the default slice as something that observably works well for throughput in fair schedulers. Acked-by: David Vernet --UHQ/JnmahpbiWvxX Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEARYKAB0WIQRBxU1So5MTLwphjdFZ5LhpZcTzZAUCZvXbGQAKCRBZ5LhpZcTz ZJskAPwItO0N37c6JNS/gLvO7148Gr6VnOK14RDnZNe4U8lAfQD/chRIfXhJ0dCS gLMMwNVwBtS1hQl1bIWcg9MQp/LteQE= =mN1L -----END PGP SIGNATURE----- --UHQ/JnmahpbiWvxX--