From owner-freebsd-hackers@freebsd.org Mon Dec 31 15:46:22 2018 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 025FE143864F for ; Mon, 31 Dec 2018 15:46:22 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-qk1-x731.google.com (mail-qk1-x731.google.com [IPv6:2607:f8b0:4864:20::731]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 6CEF9714B8 for ; Mon, 31 Dec 2018 15:46:20 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: by mail-qk1-x731.google.com with SMTP id o125so15823996qkf.3 for ; Mon, 31 Dec 2018 07:46:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=FH14VQWHLDE89wKljIBodWsN6BTeAO63TlPXD50YPFs=; b=gPTAAVflKfa4vlAqPiSAL0GfV+4csYyvH7/fU6baWuVvMD3oggmrBpsiyO1MoxC3FT +0we+PCwwhjQvnizuTDH9kwJ7al/Xx1A9Q1YURbAOFQXIts3xPOHMNW0MJBX2CTn9muh RZLdz0yGBReNukA0HIY5qBHziLonIKN7XvLJAlDJhhfm6j6Z+n54fxOijTsODd1BIFHg d5vND/gQVZ1D23Iq4ASHSUmtglr807InPKO0R4vIDxBkPnwYreLYvqbFlb6V1VOaarwV j7WYFPthOzM1M18bEuVBNNugAkAiqPRjko/8i5/b3wxIfHlWEpUFUBS+FlvOI/h8p/iU K5AA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=FH14VQWHLDE89wKljIBodWsN6BTeAO63TlPXD50YPFs=; b=jr/ph59t458aDi83LYOnCbG40q7cZt4JEWJX/CAk3GRzf511I4OaLmX9KmNQlJqDPB R9gYjK0UcNBqP6PxU81Hd/V/3x2hvABsOyn1aywmovKoDtbhga7j4uCd94Un+t2w2rG7 0QdY+CfwVkVeXE/nMotY6KXEa9UvdLbiYA9woZ0sysWaHPJTxWWv5NTr8u8YIUnfwqY5 AXugKsCLj9hS6kWBhUuAoSFbo5YR93O8VJz2mb54XLUfThZgIZwKxGmtUSKQQ+JO6/R2 pkw3tPHBG7wwTkqIWE0HRdpTeafHHG93K7kXp/LpYC3z+qdVDUCZeQ/qcyTnHMUDWQ1I DkSQ== X-Gm-Message-State: AJcUuke2KY9cQJYYILKkrBx16dt/JAK96Xt5mTpxNPulR0Baq0kbA7FD +69qzV3bjzHPW4M69yo/2UwMd5Do5qE5eoK9xOdCBzb/ X-Google-Smtp-Source: ALg8bN4w+yGiHrB6zAbBBSNCo/2uFgkBV74yFuy+mUeQFF5LY5wgdAd1taIb1JRdNo6kmjwRBWEyQiOiLP+cdcDy6e8= X-Received: by 2002:a37:c653:: with SMTP id b80mr36194474qkj.245.1546271179822; Mon, 31 Dec 2018 07:46:19 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Warner Losh Date: Mon, 31 Dec 2018 08:46:07 -0700 Message-ID: Subject: Re: Speculative: Rust for base system components To: Eric McCorkle Cc: "freebsd-hackers@freebsd.org" X-Rspamd-Queue-Id: 6CEF9714B8 X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=bsdimp-com.20150623.gappssmtp.com header.s=20150623 header.b=gPTAAVfl X-Spamd-Result: default: False [-4.96 / 15.00]; TO_DN_EQ_ADDR_SOME(0.00)[]; TO_DN_SOME(0.00)[]; DKIM_TRACE(0.00)[bsdimp-com.20150623.gappssmtp.com:+]; RCPT_COUNT_TWO(0.00)[2]; MX_GOOD(-0.01)[ALT1.aspmx.l.google.com,aspmx.l.google.com,ALT2.aspmx.l.google.com]; FORGED_SENDER(0.30)[imp@bsdimp.com,wlosh@bsdimp.com]; MIME_TRACE(0.00)[0:+,1:+]; RCVD_TLS_LAST(0.00)[]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; FROM_NEQ_ENVFROM(0.00)[imp@bsdimp.com,wlosh@bsdimp.com]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; R_DKIM_ALLOW(-0.20)[bsdimp-com.20150623.gappssmtp.com:s=20150623]; FROM_HAS_DN(0.00)[]; NEURAL_HAM_SHORT(-0.96)[-0.957,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-hackers@freebsd.org]; DMARC_NA(0.00)[bsdimp.com]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[1.3.7.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.b.8.f.7.0.6.2.list.dnswl.org : 127.0.5.0]; R_SPF_NA(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; IP_SCORE(-1.99)[ip: (-6.38), ipnet: 2607:f8b0::/32(-1.93), asn: 15169(-1.55), country: US(-0.08)] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 31 Dec 2018 15:46:22 -0000 On Mon, Dec 31, 2018 at 8:02 AM Warner Losh wrote: > > > On Sun, Dec 30, 2018 at 10:41 PM Eric McCorkle > wrote: > >> Before I begin, I want to be clear that everything here is in the realm >> of speculative, long-term discussion. My goal is to start a >> conversation, not to propose anything concrete right now. >> > > Today, this is a losing bid. The cost for rust is high (both in terms of > people and added compile time), it's not well supported on all our > architectures (and its robustness on the ones it does support has only been > tested in limited scenarios), and there's 0 software it enables from day > one. Plus, since it's a fast evolving language, we'll still need the ports > to support those things that use it today since the likelihood of a version > mismatch is high (and supporting 1 version would be a big stretch, multiple > version is right out). So any sane cost / benefit analysis says: way more > cost than benefit, forget about it. We simply don't have the man-power to > maintain a high-cost, zero-benefit component in the tree. Lord knows we > have a lot of non-zero-cost-with-almost-zero-benefit things in the tree > today that we need to get rid of. > > In the future, when there are actual replacement things written, or there > are new features written, that will shift the cost / benefit equation. And > the circumstances about what makes up base will also have shifted, if we're > lucky, and we'll be able to have a conversation. We imported perl and tcl > on the speculative notion that people would build great things. That never > really panned out, and they became a high-cost burden to keep modern for > only minor benefit. And version skew in Perl was terrible by the end. Forth > and Lua live in the tree because they have benefit (though Forth will be > departing, most likely by 13, and definitely by 14). They are also small > and easy to update to new versions. > > And we can't say, with certainty, that if a bunch of rust things show up > we'll use them in base. We'll have to see what they provide to benefit the > system. > > TBH, there's a stronger case for python than rust: there's actual python > scripts in the tree today that we have to install a port to use. And there > the benefit, while not zero, is small and the effort is large compared to > just dragging it in as a port, so it hasn't been done. It's another fast > evolving language that requires multiple versions as well... > > So write something that everybody wants, that must be in base, and that > requires rust, and then we can have the conversation... > Just re-read this. It sounds a little more negative than I wanted to come off. I'd only wanted to say today the needle is on 'nope' and I hope people write enough cool stuff to justify moving the needle off 'nope' :) The last part of that message seems more muted than I wanted. Warner