2001-04-04 02:33:20

by Simon Kirby

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Subject: 2.4.3 freeze under heavy writing + open rxvt

Three times now I've had 2.4.3 freeze on my dual CPU box while doing a
"dd if=/dev/zero of=/dev/hdc bs=1024k" (a drive to be RMA'd :)). I got
bored and opened an rxvt, and as the machine was swapping in (I assume),
everything froze. The mouse still moved for about 5 seconds before the
freeze, and the window was visible as it was attempting to start tcsh.

I'm guessing that what's happening is something is waiting on a lock and
blocking interrupts (?) for five seconds while it is swapping in, and the
NMI lockup detector is kicking in and really breaking it.

I have my serial console plugged in and minicom actually capturing now,
so I'll see if I can get a trace of some sort.

Simon-

[ Stormix Technologies Inc. ][ NetNation Communications Inc. ]
[ [email protected] ][ [email protected] ]
[ Opinions expressed are not necessarily those of my employers. ]


2001-04-04 02:40:22

by Alan

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Subject: Re: 2.4.3 freeze under heavy writing + open rxvt

> Three times now I've had 2.4.3 freeze on my dual CPU box while doing a
> "dd if=/dev/zero of=/dev/hdc bs=1024k" (a drive to be RMA'd :)). I got

Does it happen if you boot with < 900Mb of ram ?

2001-04-04 03:04:01

by John Jasen

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Subject: Re: 2.4.3 freeze under heavy writing + open rxvt

On Tue, 3 Apr 2001, Simon Kirby wrote:

> Three times now I've had 2.4.3 freeze on my dual CPU box while doing a
> "dd if=/dev/zero of=/dev/hdc bs=1024k" (a drive to be RMA'd :)). I got
> bored and opened an rxvt, and as the machine was swapping in (I assume),
> everything froze. The mouse still moved for about 5 seconds before the
> freeze, and the window was visible as it was attempting to start tcsh.
>
> I'm guessing that what's happening is something is waiting on a lock and
> blocking interrupts (?) for five seconds while it is swapping in, and the
> NMI lockup detector is kicking in and really breaking it.

I've noticed the same thing. I was doing a rather sadistic test, checking
a memory chip.

one window: make -j in 2.4.2 src; and in another, dd if=/dev/hda
of=/dev/null bs=4096k.

The third window was running top, and froze. A fourth window wouldn't get
past login:

--
-- John E. Jasen ([email protected])
-- In theory, theory and practise are the same. In practise, they aren't.

2001-04-04 13:09:25

by Athanasius

[permalink] [raw]
Subject: Re: 2.4.3 freeze under heavy writing + open rxvt

On Tue, Apr 03, 2001 at 11:02:51PM -0400, John Jasen wrote:
> On Tue, 3 Apr 2001, Simon Kirby wrote:
>
> > Three times now I've had 2.4.3 freeze on my dual CPU box while doing a
> > "dd if=/dev/zero of=/dev/hdc bs=1024k" (a drive to be RMA'd :)). I got
> > bored and opened an rxvt, and as the machine was swapping in (I assume),
> > everything froze. The mouse still moved for about 5 seconds before the
> > freeze, and the window was visible as it was attempting to start tcsh.
>
> I've noticed the same thing. I was doing a rather sadistic test, checking
> a memory chip.
>
> one window: make -j in 2.4.2 src; and in another, dd if=/dev/hda
> of=/dev/null bs=4096k.

Playing around with the Mesa3D demos last night I had 3 similar
lockups. The system is a PII-400 128MB RAM, 256MB swap on vanilla 2.4.3
(also did this on 2.4.2-ac18 as it happens). There's:

a) A similar lockup to described above, I caught my 'resetv2'
(small util to just initialise a voodoo2 then exit cleanly, or
so I thought) chewing up VM like it was going out of fashion.
Shortly thereafter solid lockup, LEDs not working etc, although
I think I forgot to try Alt-SysRq+R that time to see if the
keyboard would come back to life.

b) Running a Mesa3D demo that uses threads was fine with 3 or 5,
try it with 10, instant lockup, no magic sysrq, had to hit the
reset button. So I'd assume some other issue with threads in
2.4.3/2.4.2-ac18

-Ath
--
- Athanasius = Athanasius(at)miggy.org / http://www.miggy.org/
Finger athan(at)fysh.org for PGP key
"And it's me who is my enemy. Me who beats me up.
Me who makes the monsters. Me who strips my confidence." Paula Cole - ME