Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 20 Sep 2023 21:50:47 +0100
From:      Warner Losh <imp@bsdimp.com>
To:        Poul-Henning Kamp <phk@phk.freebsd.dk>
Cc:        Sebastian Huber <sebastian.huber@embedded-brains.de>,  "freebsd-hackers@freebsd.org" <hackers@freebsd.org>
Subject:   Re: Remove timecounter tc_counter_mask member?
Message-ID:  <CANCZdfrJJELFw2Azq35OLkYhkRXsMk2gUn-gNaP8O3syit3-0w@mail.gmail.com>
In-Reply-To: <202309191541.38JFfXnb073412@critter.freebsd.dk>
References:  <bc1a7b28-5e7b-4ee6-aae8-f95adc65fc76@embedded-brains.de> <202309162044.38GKi7RZ022115@critter.freebsd.dk> <d3e9e071-f4f9-40a9-b656-92a8853ddb08@embedded-brains.de> <202309191541.38JFfXnb073412@critter.freebsd.dk>

next in thread | previous in thread | raw e-mail | index | archive | help
--00000000000062f64d0605d0881c
Content-Type: text/plain; charset="UTF-8"

On Tue, Sep 19, 2023, 11:41 AM Poul-Henning Kamp <phk@phk.freebsd.dk> wrote:

> --------
> Sebastian Huber writes:
> > On 16.09.23 22:44, Poul-Henning Kamp wrote:
> > > Sebastian Huber writes:
> > >
> > >> the timecounter structure contains a tc_counter_mask which enables
> > >> support for time counters implementing less than 32-bits:
> > >> Is the sys/x86/isa/clock.c still used? Are there chips on the market
> > >> with 24-bit ACPI timers?
> > > ... and are there any FreeBSD platforms using narrow timecounters
> > > outside the src-tree ?
> > >
> > > My personal gut feeling, is that we can get away with it, once i386
> > > is out of the picture.
> >
> > If it is in principle acceptable to remove the tc_counter_mask at some
> > point in time, would it make sense to issue a warning if a timecounter
> > is installed with a mask not equal to 0xffffffff?
>
> It would be a good a way to warn people...
>

I'd warn on first use to cut down on the noise

Warner

-- 
> Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
> phk@FreeBSD.ORG         | TCP/IP since RFC 956
> FreeBSD committer       | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
>
>

--00000000000062f64d0605d0881c
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"auto"><div><br><br><div class=3D"gmail_quote"><div dir=3D"ltr" =
class=3D"gmail_attr">On Tue, Sep 19, 2023, 11:41 AM Poul-Henning Kamp &lt;<=
a href=3D"mailto:phk@phk.freebsd.dk">phk@phk.freebsd.dk</a>&gt; wrote:<br><=
/div><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-le=
ft:1px #ccc solid;padding-left:1ex">--------<br>
Sebastian Huber writes:<br>
&gt; On 16.09.23 22:44, Poul-Henning Kamp wrote:<br>
&gt; &gt; Sebastian Huber writes:<br>
&gt; &gt; <br>
&gt; &gt;&gt; the timecounter structure contains a tc_counter_mask which en=
ables<br>
&gt; &gt;&gt; support for time counters implementing less than 32-bits:<br>
&gt; &gt;&gt; Is the sys/x86/isa/clock.c still used? Are there chips on the=
 market<br>
&gt; &gt;&gt; with 24-bit ACPI timers?<br>
&gt; &gt; ... and are there any FreeBSD platforms using narrow timecounters=
<br>
&gt; &gt; outside the src-tree ?<br>
&gt; &gt; <br>
&gt; &gt; My personal gut feeling, is that we can get away with it, once i3=
86<br>
&gt; &gt; is out of the picture.<br>
&gt;<br>
&gt; If it is in principle acceptable to remove the tc_counter_mask at some=
 <br>
&gt; point in time, would it make sense to issue a warning if a timecounter=
 <br>
&gt; is installed with a mask not equal to 0xffffffff?<br>
<br>
It would be a good a way to warn people...<br></blockquote></div></div><div=
 dir=3D"auto"><br></div><div dir=3D"auto">I&#39;d warn on first use to cut =
down on the noise=C2=A0</div><div dir=3D"auto"><br></div><div dir=3D"auto">=
Warner</div><div dir=3D"auto"><br></div><div dir=3D"auto"><div class=3D"gma=
il_quote"><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;bord=
er-left:1px #ccc solid;padding-left:1ex">
-- <br>
Poul-Henning Kamp=C2=A0 =C2=A0 =C2=A0 =C2=A0| UNIX since Zilog Zeus 3.20<br=
>
phk@FreeBSD.ORG=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0| TCP/IP since RFC 956<br>
FreeBSD committer=C2=A0 =C2=A0 =C2=A0 =C2=A0| BSD since 4.3-tahoe=C2=A0 =C2=
=A0 <br>
Never attribute to malice what can adequately be explained by incompetence.=
<br>
<br>
</blockquote></div></div></div>

--00000000000062f64d0605d0881c--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CANCZdfrJJELFw2Azq35OLkYhkRXsMk2gUn-gNaP8O3syit3-0w>