Date: Wed, 5 Jan 2022 10:07:17 +0300 From: Mehmet Erol Sanliturk <m.e.sanliturk@gmail.com> To: Warner Losh <imp@bsdimp.com> Cc: Alexander Motin <mav@freebsd.org>, "freebsd-current@freebsd.org" <freebsd-current@freebsd.org> Subject: Re: atkbd_timeout() period? Message-ID: <CAOgwaMsBK8Wx1mD9RPaSOmS6Di237x60Oh617%2Box-1Y6RTeQmA@mail.gmail.com> In-Reply-To: <CANCZdfoF44HGN=-O1Vaxg6htA5-9=GLQDaH3nDib0SeF-bc1pg@mail.gmail.com> References: <e2c07aa3-975a-1780-d6f8-db03d12a232f@FreeBSD.org> <CANCZdfoF44HGN=-O1Vaxg6htA5-9=GLQDaH3nDib0SeF-bc1pg@mail.gmail.com>
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On Wed, Jan 5, 2022 at 9:39 AM Warner Losh <imp@bsdimp.com> wrote:
>
>
> On Tue, Jan 4, 2022 at 10:42 PM Alexander Motin <mav@freebsd.org> wrote:
>
>> Hi,
>>
>> As I see, one of the most active threaded callouts on idle VMware VM and
>> some hardware is atkbd_timeout(), called 10 times per second. Plus it
>> is also one of few remaining non-MP-safe callouts. According to the
>> comment it seems to be only a workaround for some lost interrupts. That
>> makes me thing: is it really needed to run so often and so accurate, or
>> may be we could reduce it to 1-2 times per second? Or may be it can be
>> avoided somehow 20 years later?
>>
>
> Yea, we can likely just trash it and wait for people to complain about the
> keyboard being hung. I doubt we'll get any complaints because Xaccel 2.1
> was quite a long time ago... It is no longer relevant and the original
> conditions
> that caused the lost interrupts are likely long gone...
>
> And if they aren't, we'll get a reproducible test case to judge what the
> right workaround
> should be.
>
> Warner
>
If "10" in " atkbd_timeout(), called 10 times per second "
can be defined by a control variable ,
then
it may not be necessary to remove its call , and
polling rate may be set with respect to the suitable needs .
Mehmet Erol Sanliturk
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<div dir=3D"ltr"><div dir=3D"ltr"><div class=3D"gmail_default" style=3D"fon=
t-family:tahoma,sans-serif;font-size:large"><br></div></div><br><div class=
=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Wed, Jan 5, 2022 =
at 9:39 AM Warner Losh <<a href=3D"mailto:imp@bsdimp.com">imp@bsdimp.com=
</a>> wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:=
0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">=
<div dir=3D"ltr"><div dir=3D"ltr"><br></div><br><div class=3D"gmail_quote">=
<div dir=3D"ltr" class=3D"gmail_attr">On Tue, Jan 4, 2022 at 10:42 PM Alexa=
nder Motin <<a href=3D"mailto:mav@freebsd.org" target=3D"_blank">mav@fre=
ebsd.org</a>> wrote:<br></div><blockquote class=3D"gmail_quote" style=3D=
"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-le=
ft:1ex">Hi,<br>
<br>
As I see, one of the most active threaded callouts on idle VMware VM and<br=
>
some hardware is atkbd_timeout(), called 10 times per second.=C2=A0 Plus it=
<br>
is also one of few remaining non-MP-safe callouts.=C2=A0 According to the<b=
r>
comment it seems to be only a workaround for some lost interrupts.=C2=A0 Th=
at<br>
makes me thing: is it really needed to run so often and so accurate, or<br>
may be we could reduce it to 1-2 times per second?=C2=A0 Or may be it can b=
e<br>
avoided somehow 20 years later?<br></blockquote><div><br></div><div>Yea, we=
can likely just trash it and wait for people to complain about the</div><d=
iv>keyboard being hung. I doubt we'll get any complaints because=C2=A0X=
accel 2.1</div><div>was quite a long time ago... It is no longer relevant a=
nd the original conditions</div><div>that caused the lost interrupts are li=
kely long gone...</div><div><br></div><div>And if they aren't, we'l=
l get a reproducible test case to judge what the right workaround</div><div=
>should be.</div><div><br></div><div>Warner<br></div></div></div></blockquo=
te><div><br></div><div><br></div><div><br></div><div><div style=3D"font-fam=
ily:tahoma,sans-serif;font-size:large" class=3D"gmail_default">If=C2=A0 &qu=
ot;10"=C2=A0 in=C2=A0=C2=A0 " atkbd_timeout(), called 10 times pe=
r second "<br></div></div><div><div style=3D"font-family:tahoma,sans-s=
erif;font-size:large" class=3D"gmail_default">=C2=A0=C2=A0=C2=A0=C2=A0 can =
be defined by a control variable ,</div><div style=3D"font-family:tahoma,sa=
ns-serif;font-size:large" class=3D"gmail_default">then</div><div style=3D"f=
ont-family:tahoma,sans-serif;font-size:large" class=3D"gmail_default">=C2=
=A0=C2=A0=C2=A0=C2=A0 it may not be necessary to remove its call , and</div=
><div style=3D"font-family:tahoma,sans-serif;font-size:large" class=3D"gmai=
l_default">=C2=A0=C2=A0=C2=A0=C2=A0 polling rate may be set with respect to=
the suitable needs .</div><div style=3D"font-family:tahoma,sans-serif;font=
-size:large" class=3D"gmail_default"><br></div><div style=3D"font-family:ta=
homa,sans-serif;font-size:large" class=3D"gmail_default"><br></div><div sty=
le=3D"font-family:tahoma,sans-serif;font-size:large" class=3D"gmail_default=
">Mehmet Erol Sanliturk</div><div style=3D"font-family:tahoma,sans-serif;fo=
nt-size:large" class=3D"gmail_default"><br></div><div style=3D"font-family:=
tahoma,sans-serif;font-size:large" class=3D"gmail_default"><br></div><br></=
div><div><br></div><div><br></div><div><br></div></div></div>
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