Date: Thu, 31 Dec 2020 23:20:10 +0100 From: "Kristof Provost" <kp@FreeBSD.org> To: "Rodney W. Grimes" <freebsd-rwg@gndrsh.dnsmgr.net> Cc: "Allan Jude" <allanjude@freebsd.org>, "FreeBSD Current" <freebsd-current@freebsd.org> Subject: Re: Enabling AESNI by default Message-ID: <0D67F84B-248D-4680-8D91-2CAEDCDD7ED7@FreeBSD.org> In-Reply-To: <202012312209.0BVM9HHk088051@gndrsh.dnsmgr.net> References: <202012312209.0BVM9HHk088051@gndrsh.dnsmgr.net>
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On 31 Dec 2020, at 23:09, Rodney W. Grimes wrote:
> Its for ever dead code on a large number of machines that do not have
> the hardware for it. I know that is a decreasing set, but imho it
> would be better to somehow ONLY load the module if you had CPU
> support for it. The down side is that detection would probably have
> to be in the laoder as this code can be used very early on.
>
According to kldstat it uses all of 42KB of memory.
16 1 0xffffffff83313000 a290 aesni.ko
That’s such a trivial amount of memory it’s not even worth
mentioning. Even in tiny embedded systems (and who runs tiny embedded
systems on x86?) it’s utterly insignificant.
Even if it were significant, how many of the systems without the
relevant hardware are ever going to run 13?
Regards,
Kristof
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References: <202012312209.0BVM9HHk088051@gndrsh.dnsmgr.net>
<0D67F84B-248D-4680-8D91-2CAEDCDD7ED7@FreeBSD.org>
In-Reply-To: <0D67F84B-248D-4680-8D91-2CAEDCDD7ED7@FreeBSD.org>
From: Alan Somers <asomers@freebsd.org>
Date: Thu, 31 Dec 2020 15:24:09 -0700
Message-ID: <CAOtMX2jQPXSq+VXh_-Xs+qTZTW=qNg3+-At-NH9q1QaDR0jGfg@mail.gmail.com>
Subject: Re: Enabling AESNI by default
To: Kristof Provost <kp@freebsd.org>
Cc: "Rodney W. Grimes" <freebsd-rwg@gndrsh.dnsmgr.net>,
Allan Jude <allanjude@freebsd.org>,
FreeBSD Current <freebsd-current@freebsd.org>
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On Thu, Dec 31, 2020 at 3:20 PM Kristof Provost <kp@freebsd.org> wrote:
> On 31 Dec 2020, at 23:09, Rodney W. Grimes wrote:
> > Its for ever dead code on a large number of machines that do not have
> > the hardware for it. I know that is a decreasing set, but imho it
> > would be better to somehow ONLY load the module if you had CPU
> > support for it. The down side is that detection would probably have
> > to be in the laoder as this code can be used very early on.
> >
> According to kldstat it uses all of 42KB of memory.
>
> 16 1 0xffffffff83313000 a290 aesni.ko
>
> That=E2=80=99s such a trivial amount of memory it=E2=80=99s not even wort=
h
> mentioning. Even in tiny embedded systems (and who runs tiny embedded
> systems on x86?) it=E2=80=99s utterly insignificant.
>
> Even if it were significant, how many of the systems without the
> relevant hardware are ever going to run 13?
>
> Regards,
> Kristof
>
And tiny embedded systems are probably running custom kernels anyway, so
they can remove it. I'm sold. Let's put it in GENERIC.
-Alan
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