Re: Re: [RFC][PATCH -mm][Experimental] swsusp: freeze userspace processes first

Rafael J. Wysocki
2006-02-04T21:47:19Z

Hi,

On Saturday 04 February 2006 22:26, Pavel Machek wrote:
> > > > That requires a timeout in case we have a user mode helper in the D state.
> > > > The corrected patch is appended.
> > > >
> > > > BTW, it contains a change that may help solve the unfreezeable gcc problem
> > > > that has appeared in your tests. Could you please try it or tell me what I
> > > > should do to reproduce the problem?
> > >
> > > I'm away from real macine just now... I could reproduce it with
> > > Nigel's "stress ..." command, then trying to build kernel.
> >
> > OK, I did the following:
> > 1) run "swapoff -a"
> > 2) run kernel make on one vt,
> > 3) run "stress -d 5 --hdd-bytes 100M -i 5 -c 5" on another vt,
> > 4) run "for f in 1 2 3 4 5 6 7 8 9 10; do echo disk > /sys/power/state ; sleep 5; done" on the 3rd vt.
> >
> > Appended is the version of the patch that has freezed processes in 10 attempts
> > out of 10 (please note the "if (!freezing(p))" in freeze_process() ;-)).
> >
> > Still freezing the userspace processes may take more that 15 secs under such
> > a load on my box, so the timeout is set to 20 sec (probably overkill for any
> > sane real-life situation).
>
> You have my ACK on freezer parts, but please reserve usermode helper
> parts for separate patch.

OK, I'll remove the usermodehelper-related part for now. If we have a test
case, I'll think of it again.

> Is there simple way to demonstrate usermode helper problem?

Not that I know of. Probably I am overly paranoid wrt that.

Greetings,
Rafael