2.4.3 freeze under heavy writing + open rxvt

2.4.3 freeze under heavy writing + open rxvt

[Simon Kirby]

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. ]
[       sim@stormix.com       ][       sim@netnation.com        ]
[ Opinions expressed are not necessarily those of my employers. ]

Re: 2.4.3 freeze under heavy writing + open rxvt

[Alan Cox]

> 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 ?

Re: 2.4.3 freeze under heavy writing + open rxvt

[John Jasen]

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 (jjasen1@umbc.edu)
-- In theory, theory and practise are the same. In practise, they aren't.

Re: 2.4.3 freeze under heavy writing + open rxvt

[Athanasius]

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
-- 
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