Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265716AbUF2LPf (ORCPT ); Tue, 29 Jun 2004 07:15:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265703AbUF2LPf (ORCPT ); Tue, 29 Jun 2004 07:15:35 -0400 Received: from mail016.syd.optusnet.com.au ([211.29.132.167]:50088 "EHLO mail016.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S265716AbUF2LPN (ORCPT ); Tue, 29 Jun 2004 07:15:13 -0400 Message-ID: <40E14F28.6030408@kolivas.org> Date: Tue, 29 Jun 2004 21:14:48 +1000 From: Con Kolivas User-Agent: Mozilla Thunderbird 0.7 (X11/20040615) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Pavel Machek Cc: Linux Kernel Mailinglist , Zwane Mwaikambo , William Lee Irwin III Subject: Re: [PATCH] Staircase Scheduler v6.3 for 2.6.7-rc2 References: <200406070139.38433.kernel@kolivas.org> <20040629111017.GB15414@elf.ucw.cz> In-Reply-To: <20040629111017.GB15414@elf.ucw.cz> X-Enigmail-Version: 0.84.1.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2114 Lines: 60 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Pavel Machek wrote: | Hi! | | |>This is an update of the scheduler policy mechanism rewrite using the |>infrastructure of the current O(1) scheduler. Slight changes from the |>original design require a detailed description. The change to the original |>design has enabled all known corner cases to be abolished and cpu |>distribution to be much better maintained. It has proven to be stable in my |>testing and is ready for more widespread public testing now. |> |> |>Aims: |> - Interactive by design rather than have interactivity bolted on. |> - Good scalability. |> - Simple predictable design. |> - Maintain appropriate cpu distribution and fairness. |> - Low scheduling latency for normal policy tasks. |> - Low overhead. |> - Making renicing processes actually matter for CPU distribution (nice 0 gets |>20 times what nice +20 gets) |> - Resistant to priority inversion | | | How do you solve priority inversion? I don't solve it. It is relatively resistant to priority inversion by tasks traversing all the priorities lower than itself rather than sitting at one priority. It does this more strictly when interactive is disabled which I recommend for server and multiuser setups. | Can you do "true idle threads" now? (I.e. nice +infinity?) Not safely, no. I have a batch(idle) implementation that is relatively safe but can be abused (it's in my -ck patchset only). At some stage if the codebase settles down enough I'll try and introduce semaphore tracking for batch processes that will elevate them to normal scheduling ~ to prevent DoSing. Cheers, Con -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFA4U8oZUg7+tp6mRURAircAKCSvuZ4D6rM7AsfAbHKhQoCw1C7NACaA44C UyUJAByRIE894CchzlN2OiU= =9xVI -----END PGP SIGNATURE----- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/