From nobody Tue Nov 15 17:58:04 2022 X-Original-To: freebsd-arch@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 4NBYnQ15ZPz4hMn7 for ; Tue, 15 Nov 2022 17:58:18 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-ed1-x532.google.com (mail-ed1-x532.google.com [IPv6:2a00:1450:4864:20::532]) (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 4NBYnP69J4z45xP for ; Tue, 15 Nov 2022 17:58:17 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Authentication-Results: mx1.freebsd.org; none Received: by mail-ed1-x532.google.com with SMTP id u24so22955892edd.13 for ; Tue, 15 Nov 2022 09:58:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20210112.gappssmtp.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=4d5vHEmehKHQywy87QrSFQaPj6nhf19UQuj2qx90tP8=; b=uuzjO/I+LzGwp5ra6sAGNKFdpTBlC9XcGUJs3r2cJRq/vMy8/gHi5hbghrebifjVDl x+UxR3UDVh/fcrVUOkojbZzCyAe81lMNjaNlacLk73pJ3yySTB/3X1RNGRl2hIIpckma 79a63Z7gABEaNWYvY26mwo8TBiAEmN29vqVxmRXVaVWJnfPPRIpI6XdXL3R3I8zvlmgN /7eA8aVumRkeBN71bJ5QqEXUUMJYBkBcE5yWAH2QWJcVCq6XkgcGPwdBcAbXBFZ5F8Hq 60YygJM8mnLbko5U9x2ivhUOKX8/2I7Dg7j5Pu5rN8kJCveZ7pLyT1MJsMItlB5RF/BD d8Ig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=4d5vHEmehKHQywy87QrSFQaPj6nhf19UQuj2qx90tP8=; b=y3ZAdMFzwzYNE2Kg+yxm3iamKaaCU2VIEmG9ylWxzzu6k3E164gNEMCKNLdoK4LZQB Pr7LYU1+6824jSZDuv4bKHjMc8n9RIwwLsjUbn2rDLAmhJz1Z0c0xc+yW3pBDjA6o8Ng 14uxkCbMhrXmTWuhyzwjq4yLrfJs92tvTjcz2LmtAqCIbJ1PNiBcl4wLI95DBYAHjCwv CziNiJ6oYnQuR7rf/rOBEQKzJh84x97CqBLE25AAT9pdk5sl12ROPyT9ziJvPYO2Yh83 eE7WGd+Qw/8N/dq5OBdTBjkI+ETaXk+aZlQe2zf9ggf6fT+308FVzDkR0ueY5rUgGxSX omsw== X-Gm-Message-State: ANoB5pkBguoyrHsaOBDUaz0ZqKri0M6J/LraAf3Wpe2v4XdQJA4qfxZz YGjQbcaML4igr2tfoV4nqyM9jfLgTPCYYFH2uhPDtgcDYR4= X-Google-Smtp-Source: AA0mqf6aQ8eIimKV6NRt5VxUQ+aUww7GhecREw4AdoQ+HnkZAZfInCT+BsZF6BrOdbk2lc1cFmL4vmpI8ewUW7zQNRw= X-Received: by 2002:aa7:de92:0:b0:467:8fb6:d11 with SMTP id j18-20020aa7de92000000b004678fb60d11mr12982617edv.421.1668535096168; Tue, 15 Nov 2022 09:58:16 -0800 (PST) List-Id: Discussion related to FreeBSD architecture List-Archive: https://lists.freebsd.org/archives/freebsd-arch List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-arch@freebsd.org MIME-Version: 1.0 References: In-Reply-To: From: Warner Losh Date: Tue, 15 Nov 2022 10:58:04 -0700 Message-ID: Subject: Re: Giant Locked drivers To: sgk@troutmask.apl.washington.edu Cc: "freebsd-arch@freebsd.org" Content-Type: multipart/alternative; boundary="000000000000b442b905ed86198b" X-Rspamd-Queue-Id: 4NBYnP69J4z45xP X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US] X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-ThisMailContainsUnwantedMimeParts: N --000000000000b442b905ed86198b Content-Type: text/plain; charset="UTF-8" On Tue, Nov 15, 2022 at 10:52 AM Steve Kargl < sgk@troutmask.apl.washington.edu> wrote: > On Tue, Nov 15, 2022 at 10:37:36AM -0700, Warner Losh wrote: > > > > It's no secret fiant-locked drivers' days are numbered. We've been more > > sluggish about eliminating Giant than had been hoped. I plan in the > coming > > weeks to add a tunable 'debug.giant_drivers' which initially will be set > to > > enable/disable giant-locked drivers in the tree. > > > > When set to 0, you get today's behavior. If set to 1, it will no longer > > allow drivers that don't request MPSAFE interrupt handlers from > registering > > (the interrupt setup will return an error). > > > > This will allow us to understand what is lost if we throw the switch, and > > allow users to proactively test their systems to see if they are > > affected or not (and if they are, if they want to live without the > > functionality, or want to fund work in the area). > > > > Comments? > > > > Is there a list of effected drivers? Grepping /var/run/dmesg.boot > on my system shows only "atkbd0: [GIANT-LOCKED]". A scan of atkbd(4) > shows > > This driver is required for the console driver syscons(4) or vt(4). > > So, setting debug.giant_drivers=1 will brick all FreeBSD workstations? > You could still access them via serial port or the network. And I think USB-based systems would be fine. The comment you quoted is slightly overstated. And yes, the point is to show the pain and get people to get off their !$#^ and do something if they care. Warner --000000000000b442b905ed86198b Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


=
On Tue, Nov 15, 2022 at 10:52 AM Stev= e Kargl <sgk@troutma= sk.apl.washington.edu> wrote:
On Tue, Nov 15, 2022 at 10:37:36AM -0700, Warner Losh = wrote:
>
> It's no secret fiant-locked drivers' days are numbered. We'= ;ve been more
> sluggish about eliminating Giant than had been hoped. I plan in the co= ming
> weeks to add a tunable 'debug.giant_drivers' which initially w= ill be set to
> enable/disable giant-locked drivers in the tree.
>
> When set to 0, you get today's behavior. If set to 1, it will no l= onger
> allow drivers that don't request MPSAFE interrupt handlers from re= gistering
> (the interrupt setup will return an error).
>
> This will allow us to understand what is lost if we throw the switch, = and
> allow users to proactively test their systems to see if they are
> affected or not (and if they are, if they want to live without the
> functionality, or want to fund work in the area).
>
> Comments?
>

Is there a list of effected drivers?=C2=A0 Grepping /var/run/dmesg.boot
on my system shows only "atkbd0: [GIANT-LOCKED]".=C2=A0 A scan of= atkbd(4)
shows

=C2=A0 =C2=A0This driver is required for the console driver syscons(4) or v= t(4).

So, setting debug.giant_drivers=3D1 will brick all FreeBSD workstations?

You could still access them via serial po= rt or the network.

And I think USB-based systems w= ould be fine. The comment you quoted is slightly overstated.

=
And yes, the point is to show the pain and get people to get off= their !$#^ and do something if they care.

Warner<= /div>
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