Date: Sat, 28 Jul 2007 17:36:21 +0400 (MSD) From: Dmitry Morozovsky <marck@rinet.ru> To: Maksim Yevmenkin <maksim.yevmenkin@gmail.com> Cc: current@freebsd.org Subject: Re: possible showstopper: kbdmux hangs -current Message-ID: <20070728173355.O42349@woozle.rinet.ru> In-Reply-To: <bb4a86c70707271018p45f3ccbap142bd6506c4dfc46@mail.gmail.com> References: <20070727141421.H42349@woozle.rinet.ru> <bb4a86c70707271018p45f3ccbap142bd6506c4dfc46@mail.gmail.com>
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On Fri, 27 Jul 2007, Maksim Yevmenkin wrote:
MY> On 7/27/07, Dmitry Morozovsky <marck@rinet.ru> wrote:
MY> > Hi there,
MY> >
MY> > on some of my mobos -current hangs early (when starning init) if kbdmux is
MY> > included in kernel (both on i386 and amd64); this seems to be some race, as
MY> > hangs are not 100% reproducible. What info should I provide to debug?
MY>
MY> the usual suspects are
MY>
MY> 1) while (KBDMUX_CHECK_CHAR(kbd)) { ... } loop in kbdmux_kbd_event().
MY> could you please try to put some debug printf's into it and make sure
MY> it does not stuck there.
errrm. Added two printfs with ppsratecheck - and, as usual, 'specialist
presense effect' is in place: no single hang since, both on stock GENERIC and
my own stripped down kernel so far (approx 20 reboots).
Will try further.
MY>
MY> 2) callout. kbdmux callout initialized as non mp-safe to make sure
MY> giant is held.
MY>
MY> 3) task queue. kbdmux(4) uses taskqueue_swi_giant.
MY>
MY> you might want to try uncomment section at line 81 in kbdmux.c. this
MY> should add private lock for kbdmux(4). not sure it will work though -
MY> many things has changed since i tried it.
MY>
MY> > I'm using only PS2 keyboards, and have no other format keyboards handy;
MY> > however, I can obtain USB keyb if needed.
MY>
MY> are you using ps/2 mouse? if so, try to disconnect it and see if this helps.
No, there is no mouse attached.
Sincerely,
D.Marck [DM5020, MCK-RIPE, DM3-RIPN]
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*** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck@rinet.ru ***
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