From nobody Tue Nov 30 16:32:37 2021 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 DC3A818BE113 for ; Tue, 30 Nov 2021 16:32:37 +0000 (UTC) (envelope-from shawn.webb@hardenedbsd.org) Received: from mail-qt1-x835.google.com (mail-qt1-x835.google.com [IPv6:2607:f8b0:4864:20::835]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4J3SS55MH6z4TJk for ; Tue, 30 Nov 2021 16:32:37 +0000 (UTC) (envelope-from shawn.webb@hardenedbsd.org) Received: by mail-qt1-x835.google.com with SMTP id z9so20763234qtj.9 for ; Tue, 30 Nov 2021 08:32:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=hardenedbsd.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=U9I/+MA0G9MOKdkiuZAtIU0zpQLX272U3CfJelB0dPU=; b=dP8/EYssKq75MCPRc/Cf3FHV3iMEP2jPAf0PqMr6gJBtpLMpWDbDnK8USsBaT7bMbL mZsUKqsKaFVXGbpOQ4NYvKxhdYet17m6+gofXgNVi0koc+l5Mf3S+MFxf4FUgClp0qSM K7DpdAwANtiGgGplqMVgOqkcOr2yyadCrHMB6lZq6u9jhukOg6tsM7vDyTCzlfXMbVkL JGwXCqNL04nzHjnj8VKoJ/bjNWQgQstT3vk8E9bdElIz7P7xnjc9Gp3S95RIv8tSGMxn lUVoAKNolLfpCxCt85UFVGoGnHyon1es3QwWiTOAlesLlqxauip6h4cF288frm+w+sPA CDyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=U9I/+MA0G9MOKdkiuZAtIU0zpQLX272U3CfJelB0dPU=; b=Tx+ILZTeimlWaIbk7Axs/ddPfogxmdQABe4r/X8Xt1ZbUXq1IbRK0papMX1z5Acv7L aAAzoHRI1L8fZKKXDNZrHiAs9pHERPxnO6laY/L1VUv13H+Uxy/5keWNjn6KBGgHuh3L boGHA3xfqEUpDBs8+6k86jKd9eq/+V9kMunppcfxAhKi5X++7LpRzwehbZDeRtOFmef7 e3PfN6xiQCvvtCHYHj5Sg4NWzTSDMtBJiiNSnM9oLC2cqTdF9+VGrBrhw7mDG6XodrXj gRmBctfDsamT0ZrISxtoITnSNqEg522ltE7aSWM1o+qorxVkDwQfARzWQe7nznNXHi7z CiwQ== X-Gm-Message-State: AOAM53352IrlH5br3PSkJet8UGlOVUQzjyIWvaXngYDnXYhbgKbomsJa 6M4pPUV1mDMXivVJeIO+CQDavg== X-Google-Smtp-Source: ABdhPJzK4gC88sbrQTkMq3t5uMX5cBfyCoCeqcCVI+Zl+KqydznHxaIPQYPCMubYeCWKrTKAW0yYGg== X-Received: by 2002:a05:622a:1310:: with SMTP id v16mr382089qtk.431.1638289957324; Tue, 30 Nov 2021 08:32:37 -0800 (PST) Received: from mutt-hbsd ([38.140.209.220]) by smtp.gmail.com with ESMTPSA id w10sm10141573qkp.121.2021.11.30.08.32.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Nov 2021 08:32:36 -0800 (PST) Date: Tue, 30 Nov 2021 11:32:37 -0500 From: Shawn Webb To: Stefan Esser Cc: Joseph Mingrone , FreeBSD Hackers Subject: Re: Call for Foundation-supported Project Ideas Message-ID: <20211130163237.hdfl7bsthccbxo7l@mutt-hbsd> X-Operating-System: FreeBSD mutt-hbsd 14.0-CURRENT-HBSD FreeBSD 14.0-CURRENT-HBSD X-PGP-Key: https://git.hardenedbsd.org/hardenedbsd/pubkeys/-/blob/master/Shawn_Webb/03A4CBEBB82EA5A67D9F3853FF2E67A277F8E1FA.pub.asc References: <861r36xzpe.fsf@phe.ftfl.ca> 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 MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="x37rvubhivh732aa" Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 4J3SS55MH6z4TJk X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[] X-ThisMailContainsUnwantedMimeParts: N --x37rvubhivh732aa Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Nov 30, 2021 at 12:53:20PM +0100, Stefan Esser wrote: > Am 23.11.21 um 23:41 schrieb Joseph Mingrone: > > Hello FreeBSD community, > >=20 > > The Foundation is seeking suggestions for new projects to support. What > > gaps in the Project are not being addressed by the broader community? >=20 > The "new" ULE scheduler has a number of well-known issues, which leads > to the "old" BSD scheduler giving better performance on many systems > and loads, but is based on concepts that made sense in pre-SMP times. >=20 > ULE suffers from pathological behavior in many scenarios, and it does > not know how to best deal with simultaneous multi-threading, big/little > architectures, or the effects of virtualization. >=20 > ULE does not care for the "niceness" of a process and lets nice -19 > processes run with hardly any reduction of the share of CPU cycles > granted compared to competing nice 0 processes, for example. >=20 > Virtualization gives a number of additional requirements and restrictions > in both the host and client. Schedulers in other operating systems have > been modified to reduce the risk of side-channel attacks by running only > processes for one user at a time on the virtual processors of an SMT core. >=20 > Within a virtual machine, the real topology of the underlying hardware > may be hidden and scheduling effects by the VM host may need to be taken > into consideration (e.g. clock variations and "time jumps"). There is > a connection to bhyve, at least (perhaps also to other virtualization > platforms) that has to be taken into account. >=20 > Another aspect is optimization for performance vs. optimization for > low power use, which both require a specific scheduling strategy on > complex CPU topologies. >=20 > IMHO, a scheduler design that is based on experiences gained by other > projects and our knowledge of deficiencies of the currently available > schedulers in FreeBSD under specific loads could be a huge win for the > project. >=20 > This would be a long-term project, and I do not see any developer > currently working on designing or implementing a new scheduler. >=20 > There have been minor changes to SCHED_ULE, recently, but I'd think > that a completely new design will be required, based on knowledge > gained in the last 1 or 2 decades and able to deal with architectural > changes that have occurred in that time frame. I also wonder how the recent push to big.little on multiple CPU architectures affects FreeBSD and how we could support it. Thanks, --=20 Shawn Webb Cofounder / Security Engineer HardenedBSD https://git.hardenedbsd.org/hardenedbsd/pubkeys/-/raw/master/Shawn_Webb/03A= 4CBEBB82EA5A67D9F3853FF2E67A277F8E1FA.pub.asc --x37rvubhivh732aa Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEA6TL67gupaZ9nzhT/y5nonf44foFAmGmUiIACgkQ/y5nonf4 4forKg/+KPAYRJRx3csbecFMw7k6q+RMUn1Tn8Gf+SGzLvTltl0wMKOZqR/v3Wa3 MuOop1kTFBquT9rzdtlcxH9LkVoRyVjM4Vdm7lBQnRT2oyhe8R7EP7STlQV+wAlF ntRk9Mz1yj2c41/G+T7J3bRU2VW9fw3oMPXQ7s8Pe562oeD6kqifF8wZkQp3xFpv ZaZZ3YYVwuce7KEaA8whUjAhcZ2QnGHpOH1599BtNOC9sekgXKmx69MtJUa+eff/ YsZ70EzRLNa5rosbBY8fqojyNnJ6HuogC8HRn9RiId38LpiCv5g4ORDCENviD4Rv YDLO7ZSd0NdvaUzGFrvZSH6L1gZFeWuyiDy7UvNJJaBtvCtQrQrGvGzRn5HEjoPb k7ymZ1v4Wi0hZ/D3bFOdUat0TErnzSiY1ad9ssVKvSMk6mubLGlrfj9jv6AtGbV3 IqSbjMRmk5Pop6BiNhddF2ffOqkeAvNxHcr+HGcWO3oALAyCU/vmafFviM6TqI8o 9jpHB+WVOODP7VvshiwGkeWmutc/JRv3//RzW1rAIk8srlCTeZoB5bExbxPIbdqa 9oxNfdobA/HZ5cjtl6jWunO2+UcwrQ5DmzDo0hmw/RiEpYBMw1F4LQgjAmY8KiVd ELSByXV6wfMxr9HbsaSKoOdgawANT6oSVWOvUTDzG3yOs/5Op2Y= =fhGt -----END PGP SIGNATURE----- --x37rvubhivh732aa--