On Sat, 2014-03-22 at 07:57 +0530, Srikar Dronamraju wrote:
> > > So reverting and applying v3 3/4 and 4/4 patches works for me.
> >
> > Ok, I verified that the above endds up resulting in the same tree as
> > the minimal patch I sent out, modulo (a) some comments and (b) an
> > #ifdef CONFIG_SMP
> > So reverting and applying v3 3/4 and 4/4 patches works for me.
>
> Ok, I verified that the above endds up resulting in the same tree as
> the minimal patch I sent out, modulo (a) some comments and (b) an
> #ifdef CONFIG_SMP in futex_get_mm() that doesn't really matter.
>
> So I committed the
On Thu, Mar 20, 2014 at 9:55 PM, Srikar Dronamraju
wrote:
>
> I reverted commits 99b60ce6 and b0c29f79. Then applied the patches in
> the above url. The last one had a reject but it was pretty
> straightforward to resolve it. After this, specjbb completes.
>
> So reverting and applying v3 3/4 and
>
> Ok, so a big reason why this patch doesn't apply cleanly after reverting
> is because *most* of the changes were done at the top of the file with
> regards to documenting the ordering guarantees, the actual code changes
> are quite minimal.
>
> I reverted commits 99b60ce6 (documentation) and
On Thu, Mar 20, 2014 at 1:20 PM, Davidlohr Bueso wrote:
>
> I reverted commits 99b60ce6 (documentation) and b0c29f79 (the offending
> commit), and then I cleanly applied the equivalent ones from v3 of the
> series (which was already *tested* and ready for upstream until you
> suggested looking int
On Thu, 2014-03-20 at 09:31 -0700, Davidlohr Bueso wrote:
> hmmm looking at ppc spinlock code, it seems that it doesn't have ticket
> spinlocks -- in fact Torsten Duwe has been trying to get them upstream
> very recently. Since we rely on the counter for detecting waiters, this
> might explain the
On Thu, 2014-03-20 at 12:25 -0700, Linus Torvalds wrote:
> On Thu, Mar 20, 2014 at 12:08 PM, Davidlohr Bueso wrote:
> >
> > Oh, it does. This atomics technique was tested at a customer's site and
> > ready for upstream.
>
> I'm not worried about the *original* patch. I'm worried about the
> incre
On Thu, Mar 20, 2014 at 12:08 PM, Davidlohr Bueso wrote:
>
> Oh, it does. This atomics technique was tested at a customer's site and
> ready for upstream.
I'm not worried about the *original* patch. I'm worried about the
incremental one.
Your original patch never applied to my tree - I think it
On Thu, 2014-03-20 at 11:36 -0700, Linus Torvalds wrote:
> On Thu, Mar 20, 2014 at 10:18 AM, Davidlohr Bueso wrote:
> >
> > Comparing with the patch I sent earlier this morning, looks equivalent,
> > and fwiw, passes my initial qemu bootup, which is the first way of
> > detecting anything stupid g
On Thu, Mar 20, 2014 at 10:18 AM, Davidlohr Bueso wrote:
>
> Comparing with the patch I sent earlier this morning, looks equivalent,
> and fwiw, passes my initial qemu bootup, which is the first way of
> detecting anything stupid going on.
>
> So, Srikar, please try this patch out, as opposed to m
On Thu, Mar 20, 2014 at 11:03 AM, Davidlohr Bueso wrote:
>
> I still wonder about ppc and spinlocks (no ticketing!!) ... sure the
> "waiters" patch might fix the problem just because we explicitly count
> the members of the plist. And I guess if we cannot rely on all archs
> having an equivalent s
On Thu, 2014-03-20 at 10:42 -0700, Linus Torvalds wrote:
> On Thu, Mar 20, 2014 at 10:18 AM, Davidlohr Bueso wrote:
> >> It strikes me that the "spin_is_locked()" test has no barriers wrt the
> >> writing of the new futex value on the wake path. And the read barrier
> >> obviously does nothing wrt
On Thu, Mar 20, 2014 at 10:18 AM, Davidlohr Bueso wrote:
>> It strikes me that the "spin_is_locked()" test has no barriers wrt the
>> writing of the new futex value on the wake path. And the read barrier
>> obviously does nothing wrt the write either. Or am I missing
>> something? So the write tha
On Thu, 2014-03-20 at 09:41 -0700, Linus Torvalds wrote:
> On Wed, Mar 19, 2014 at 10:56 PM, Davidlohr Bueso wrote:
> >
> > This problem suggests that we missed a wakeup for a task that was adding
> > itself to the queue in a wait path. And the only place that can happen
> > is with the hb spinloc
On Wed, Mar 19, 2014 at 10:56 PM, Davidlohr Bueso wrote:
>
> This problem suggests that we missed a wakeup for a task that was adding
> itself to the queue in a wait path. And the only place that can happen
> is with the hb spinlock check for any pending waiters.
Ok, so thinking about hb_waiters_
On Wed, 2014-03-19 at 22:56 -0700, Davidlohr Bueso wrote:
> On Thu, 2014-03-20 at 11:03 +0530, Srikar Dronamraju wrote:
> > > > Joy,.. let me look at that with ppc in mind.
> > >
> > > OK; so while pretty much all the comments from that patch are utter
> > > nonsense (what was I thinking), I canno
On Thu, 2014-03-20 at 15:38 +0530, Srikar Dronamraju wrote:
> > This problem suggests that we missed a wakeup for a task that was adding
> > itself to the queue in a wait path. And the only place that can happen
> > is with the hb spinlock check for any pending waiters. Just in case we
> > missed s
> This problem suggests that we missed a wakeup for a task that was adding
> itself to the queue in a wait path. And the only place that can happen
> is with the hb spinlock check for any pending waiters. Just in case we
> missed some assumption about checking the hash bucket spinlock as a way
> of
On Thu, Mar 20, 2014 at 11:03:50AM +0530, Srikar Dronamraju wrote:
> > > Joy,.. let me look at that with ppc in mind.
> >
> > OK; so while pretty much all the comments from that patch are utter
> > nonsense (what was I thinking), I cannot actually find a real bug.
> >
> > But could you try the be
On Thu, 2014-03-20 at 11:03 +0530, Srikar Dronamraju wrote:
> > > Joy,.. let me look at that with ppc in mind.
> >
> > OK; so while pretty much all the comments from that patch are utter
> > nonsense (what was I thinking), I cannot actually find a real bug.
> >
> > But could you try the below whi
> > Joy,.. let me look at that with ppc in mind.
>
> OK; so while pretty much all the comments from that patch are utter
> nonsense (what was I thinking), I cannot actually find a real bug.
>
> But could you try the below which replaces a control dependency with a
> full barrier. The control flow
On Wed, 2014-03-19 at 18:08 +0100, Peter Zijlstra wrote:
> On Wed, Mar 19, 2014 at 04:47:05PM +0100, Peter Zijlstra wrote:
> > > I reverted b0c29f79ecea0b6fbcefc999e70f2843ae8306db on top of v3.14-rc6
> > > and confirmed that
> > > reverting the commit solved the problem.
> >
> > Joy,.. let me lo
On Wed, Mar 19, 2014 at 04:47:05PM +0100, Peter Zijlstra wrote:
> > I reverted b0c29f79ecea0b6fbcefc999e70f2843ae8306db on top of v3.14-rc6 and
> > confirmed that
> > reverting the commit solved the problem.
>
> Joy,.. let me look at that with ppc in mind.
OK; so while pretty much all the commen
On Wed, Mar 19, 2014 at 8:26 AM, Srikar Dronamraju
wrote:
>
> I reverted b0c29f79ecea0b6fbcefc999e70f2843ae8306db on top of v3.14-rc6 and
> confirmed that
> reverting the commit solved the problem.
Ok. I'll give Peter and Davidlohr a few days to perhaps find something
obvious, but I guess we'll
> >
> > Infact I can reproduce this if the java_constraint is either node, socket,
> > system.
> > However I am not able to reproduce if java_constraint is set to core.
>
> What's any of that mean?
>
Using the constraint, one can specify how many jvm instances should
participate in the specjbb
On Wed, Mar 19, 2014 at 08:56:19PM +0530, Srikar Dronamraju wrote:
> There are 332 tasks all stuck in futex_wait_queue_me().
> I am able to reproduce this consistently.
>
> Infact I can reproduce this if the java_constraint is either node, socket,
> system.
> However I am not able to reproduce if
26 matches
Mail list logo
