From nobody Thu Mar 23 10:26:44 2023 X-Original-To: freebsd-hackers@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4Pj1jW2m8Gz419MH for ; Thu, 23 Mar 2023 10:26:55 +0000 (UTC) (envelope-from mad@madpilot.net) Received: from mail.madpilot.net (vogon.madpilot.net [159.69.1.99]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4Pj1jW0Xtlz44d9; Thu, 23 Mar 2023 10:26:55 +0000 (UTC) (envelope-from mad@madpilot.net) Authentication-Results: mx1.freebsd.org; none Received: from mail (mail [192.168.254.3]) by mail.madpilot.net (Postfix) with ESMTP id 4Pj1jM0kdGz6dsH; Thu, 23 Mar 2023 11:26:47 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=madpilot.net; h= content-transfer-encoding:content-type:content-type:in-reply-to :from:from:content-language:references:subject:subject:date:date :message-id:received; s=bjowvop61wgh; t=1679567205; x= 1681381606; bh=+EXBD6k84ysDFiw2NKtYQ+YyVhiKal3QC6OcwFFaPfY=; b=O QG70QarAdOQ8X0gVmkpyG0aMJ78I79+RIGtNpPdSK+9gzt7t5IBS8ayO+WGvPZD6 FN0JMCegBMCBUjJUnNeIGlNKV3O2kvTjHlHuap5vT8eRWL0XTWUzAg8ZqT8gKntg 8Gyny5eHA5L1CRcADYiIX3nOoszmE7X9BHkit5KIlPnP/ZtKM0Gi9onIXFaIzAL+ 3CuOLnDTE8U+sf+GOBQR8r+s6K3mOoK9fH5G6c40Gz4N90rlGqcdYoixbljs4MGh hBIAtH4HaL3ILdfcnQx6CYpmcGaNfta/5Z5RKHs+CC5kJMf5MtcdO8Or/u5OsNiI 4F5dLCyzmhBR14cGVjsJg== Received: from mail.madpilot.net ([192.168.254.3]) by mail (mail.madpilot.net [192.168.254.3]) (amavisd-new, port 10026) with ESMTP id OsCbKGZW6YPg; Thu, 23 Mar 2023 11:26:45 +0100 (CET) Message-ID: <2de839ad-1af9-7930-c294-7523a2892649@madpilot.net> Date: Thu, 23 Mar 2023 11:26:44 +0100 Subject: Re: Periodic rant about SCHED_ULE To: David Chisnall , freebsd-hackers@freebsd.org References: <202303221710.32MHAhe9047582@gndrsh.dnsmgr.net> <27f46bc2-54f8-f5aa-79ca-184e86d185d8@m5p.com> Content-Language: en-US From: Guido Falsi In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4Pj1jW0Xtlz44d9 X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:24940, ipnet:159.69.0.0/16, country:DE] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-ThisMailContainsUnwantedMimeParts: N List-Id: Technical discussions relating to FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-hackers List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-hackers@freebsd.org On 23/03/23 11:03, David Chisnall wrote: > On 22/03/2023 18:03, George Mitchell wrote: >> Rebuilding the kernel is the only way I know.  In an ideal world, the >> scheduler would be a loadable kernel module (if that's even possible), > > Solaris supports multiple schedulers, as I believe does Linux, but I > think in both cases it's a boot-time option.  It's been too long since I > looked at the early boot order to know if there's anything that handles > linking the loader-provided modules that depends on any scheduler data > structures.  Doing that audit and ensuring that there aren't would be > the first step.  From there, it should be mostly build-system > infrastructure to allow building the two schedulers as modules and > switching between them at boot. I guess this will be somewhat provided once we get pkgbase. At that point multiple kernel packages can be distributed and the user chooses which one gets loaded. -- Guido Falsi