Date: Mon, 7 Dec 2015 10:09:42 -0500 (EST) From: Rick Macklem <rmacklem@uoguelph.ca> To: Alexander Kabaev <kabaev@gmail.com> Cc: FreeBSD Current <freebsd-current@freebsd.org> Subject: Re: slow screen updates on laptop console (i386) Message-ID: <697195597.121770130.1449500982738.JavaMail.zimbra@uoguelph.ca> In-Reply-To: <20151207091815.16e11a13@kan> References: <900422043.121631608.1449496955386.JavaMail.zimbra@uoguelph.ca> <20151207091815.16e11a13@kan>
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Alexander Kabaev wrote: > On Mon, 7 Dec 2015 09:02:35 -0500 (EST) > Rick Macklem <rmacklem@uoguelph.ca> wrote: > > > Hi, > > > > When running FreeBSD-current on an old i386 laptop, the console > > screen is intermittently slow to display output. The hesitations > > can be several seconds. > > Sometimes it shows up when I'm typing such that it takes seconds > > for the characters to echo. > > I think it is the display/output side, since I've seen it happen when > > doing "more <file>", where the screen is stuck half way through > > displaying the page for a few seconds. > > > > I don't see any problem when going into the machine remotely and > > I don't see the problem on the other laptop I have running > > FreeBSD/amd64. > > > > It has been happening for a while. It occurs on the oldest kernel > > I have lying around (r287930, Sep. 17, 2015). > > > > I've tried the old "sc" driver and it seems to happen less with it, > > but it still occurs. > > > > I'll admit I have no idea what drives doing output for the display > > screen. > > > > Anyone have ideas w.r.t. this? > > > > Thanks in advance, rick > > Hi, > > maybe a stretch, but I would try selecting different eventtimer, if > available. Say, I had to select HPET on my old i7 920 to make timeouts > run reliably. > > sysctl kern.eventtimer.timer=HPET > Great guess! Actually this old laptop doesn't have HPET, but switching it from LAPIC->RTC seems to have fixed the problem. (I had a hunch it was something timer/interrupt related, but I don't know that part of the system.) --> Just fyi, my other laptop that works fine defaulted to HPET. It looks like HPET rates higher than LAPIC. Thanks a lot, rick > -- > Alexander Kabaev >
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