Andrea Arcangeli [andrea@suse.de] wrote:
> On Thu, Apr 26, 2001 at 12:38:02AM -0500, Bob McElrath wrote:
> > When I posted this bug originally, you came right out and said it was
> > probably the rwsemaphores. I really have no idea how the rwsemaphores
>
> You were talking about the ps table hang when I told you about the rwsem
> races. I had the same trouble on my alpha and I reproduced the races
> trivially by lanucing:
>
> make MAKE='make -j2' -j2 &
>
> while :; do ps xa ; sleep 1 ; done
>
> After a few seconds ps deadlocked. Try that on the old asm semaphores.
This does not cause a hang on my machine with your new rwsemaphores.
> It was 100% reproducible, and after I rewrote the rwsemaphores the
> deadlock gone away completly.
>
> Your X hanging in R state is completly unrelated to the rwsem ps table
> hang problem as far I can tell.
Ok, so what are the other alternatives? In the R state, the scheduler
should give it some CPU at the first available jiffy, correct? After
several minutes it was still stuck in the R state, and had received 0
CPU time.
Could this be a scheduler bug?
Another thing I just noticed: watching the ps list, gcc is getting
called with -mcpu=ev56, which in turn is calling as with -mev6. Since
this is an ev56 processor, not the newer ev6, this could conceivable be
generating illegal instructions, though I haven't ever seen any kernel
illegal instruction faults.
*Sigh*
-- Bob
Bob McElrath (rsmcelrath@students.wisc.edu)
Univ. of Wisconsin at Madison, Department of Physics
This archive was generated by hypermail 2b29 : Mon Apr 30 2001 - 21:00:16 EST