Date: Tue, 4 Jan 2022 23:39:01 -0700 From: Warner Losh <imp@bsdimp.com> To: Alexander Motin <mav@freebsd.org> Cc: "freebsd-current@freebsd.org" <freebsd-current@freebsd.org> Subject: Re: atkbd_timeout() period? Message-ID: <CANCZdfoF44HGN=-O1Vaxg6htA5-9=GLQDaH3nDib0SeF-bc1pg@mail.gmail.com> In-Reply-To: <e2c07aa3-975a-1780-d6f8-db03d12a232f@FreeBSD.org> References: <e2c07aa3-975a-1780-d6f8-db03d12a232f@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--000000000000ffafd105d4d002a1 Content-Type: text/plain; charset="UTF-8" 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 --000000000000ffafd105d4d002a1 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <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">mav@freebsd.org</a>> w= rote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0p= x 0.8ex;border-left:1px solid rgb(204,204,204);padding-left: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><br></div></div><= /div> --000000000000ffafd105d4d002a1--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CANCZdfoF44HGN=-O1Vaxg6htA5-9=GLQDaH3nDib0SeF-bc1pg>