Re: 2.4.20: Proccess stuck in __lock_page ...

[Andrea Arcangeli]

On Thu, May 29, 2003 at 04:10:34PM +0200, Matthias Mueller wrote:
> On Thu, May 29, 2003 at 03:19:37PM +0200, Andrea Arcangeli wrote:
> > On Wed, May 28, 2003 at 02:10:40PM +0200, Matthias Mueller wrote:
> > > Tested all of them and some combinations:
> > > patch 1 alone: still mouse hangs
> > > patch 2 alone: still mouse hangs
> > > patch 3 alone: no hangs, but I get some zombie process (starting a lot of
> > >                xterms results in zombie xterms, not noticed with vanilla
> > >                and the other patches)
> > > patch 1+2: no mouse hangs
> > > patch 1+2+3: no mouse hangs, no zombies
> > 
> > I can't find a sense in the zombie thing, how can you generate zombie at
> > all from xterms? That sounds like your userspace is terribly broken and
> > it may have race conditions or whatever. In no way those patches can
> > generate or not-generate zombies from xterms. I never ever seen a zombie
> > xterm in my whole linux experience.
> 
> I rechecked everything an noticed, that it wasn't a xterm, but a wrapper
> script, that executed rxvt. I changed that to plain xterm and the zombies
> were gone. So I think there was probably a bug in rxvt triggered there.
> After that I redid the tests, with the same result (and no zombies).
> I can feel no difference between 1+2 or 1+2+3.

this sounds very sane now thanks for fixing the issues with the zombies!

it also makes sense to me that 1+2 is the same as 1+2+3, because I'd be
very surprised if the (purely smp) race condition in 3 made a whole lot
of difference for interactivity of a large write.

Andrea