Re: [BUG] Strange 1-second pauses during Resume-from-RAM

Jörn Engel
2007-12-01T17:50:03Z

On Fri, 30 November 2007 19:46:25 +0100, Ingo Molnar wrote:
> * Jörn Engel <joern@logfs.org> wrote:
> >
> > It compiles. It boots with a 512M RAM (384M was too little with all
> > the other debug options on). But it seems to lock up when running
> > trace-cmd. On a rerun it locks up again, but with different output.
>
> hm, you should decrease MAX_TRACE in kernel/latency_tracing.c from 1
> million to 16K or so. 1 million entries probably depletes lowmem quite
> seriously.

That's ok. RAM is cheap.

> > Rerun was captured:
> > http://logfs.org/~joern/trace1.jpg
>
> hm, that looks weird. if you disable CONFIG_PROVE_LOCKING, does that
> improve things? (or just turns a noisy lockup into a silent lockup?)

Not much, although the dumps look different now:
http://logfs.org/~joern/trace3.jpg
http://logfs.org/~joern/trace4.jpg

I have to change my qemu setup a little to see the top of those
dumps...

> > I should do a couple of runs, but my girlfriend claims realtime
> > priority for the evening.
>
> yeah, SCHED_IDLE is not generally well received by them.

...as soon as more urgent tasks has finished (weekend is over).

Jörn

--
It does not matter how slowly you go, so long as you do not stop.
-- Confucius