Re: REGRESSION: 3.10-rc1: Dell Latitude e6410 hangs within 3 seconds

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

On Sat, May 18, 2013 at 09:14:25AM +0200, Arend van Spriel wrote:
> On 05/18/13 03:47, Paul E. McKenney wrote:
> >On Fri, May 17, 2013 at 10:49:16PM +0200, Arend van Spriel wrote:
> >>On 05/14/2013 10:38 PM, Arend van Spriel wrote:
> >>>On 05/14/2013 10:34 PM, Rafael J. Wysocki wrote:
> >>>>On Tuesday, May 14, 2013 03:03:58 PM Arend van Spriel wrote:
> >>>>>Laptop hangs pretty soon after booting. Workaround for me was to turn
> >>>>>off ACPI on kernel command line, ie. acpi=off
> >>>>>
> >>>>>Attached is my kernel configuration.
> >>>>
> >>>>Well, I have no idea what may be the source of this.
> >>>
> >>>Me neither.
> >>>
> >>>>Any chance to bisect?
> >>>
> >>>can try. Rebuilding kernels can be a drag :-p
> >>>
> >>>Regards,
> >>>Arend
> >>
> >>Hi Rafael,
> >>
> >>The bisect result found commit c0f4dfd4f as culprit. I also verified
> >>that the merge into Linus' tree introduced the issue upstream, ie.
> >>6c24499 works and 1f889ec does not. I tried to revert the commit,
> >>but that was a bit risky (conflict to resolve) and did not give me a
> >>stable kernel. The only thing that works is selecting acpi=off. I
> >>tried also nohz=off but that resulted in /init failure.
> >>
> >>Regards,
> >>Arend
> >>
> >>---8<----------------------------------------------------------------
> >>
> >>commit 1f889ec62c3f0d8913f3c32f9aff2a1e15099346
> >>   Merge: 6c24499 8fcfae3
> >>
> >>   commit 8fcfae31719c0a6c03f2cf63f815b46d378d8be4
> >>     Merge: d02a9a8 6d87669
> >>
> >>     commit 6d87669357936bffa1e8fea7a4e7743e76905736
> >>       Merge: 3f944ad 81e5949 910ee45
> >>
> >>       commit c0f4dfd4f90f1667d234d21f15153ea09a2eaa66
> >>       Author: Paul E. McKenney<paul.mckenney@linaro.org>
> >>       Date:   Fri Dec 28 11:30:36 2012 -0800
> >>
> >>           rcu: Make RCU_FAST_NO_HZ take advantage of numbered callbacks
> >>
> >>           Because RCU callbacks are now associated with the number
> >>           of the grace period that they must wait for, CPUs can now
> >>           take advance callbacks corresponding to grace periods that
> >>           ended while a given CPU was in dyntick-idle mode. This
> >>           eliminates the need to try forcing the RCU state machine
> >>           while entering idle, thus reducing the CPU intensiveness
> >>           of RCU_FAST_NO_HZ, which should increase its energy
> >>           efficiency.
> >>
> >>       Signed-off-by: Paul E. McKenney<paul.mckenney@linaro.org>
> >>       Signed-off-by: Paul E. McKenney<paulmck@linux.vnet.ibm.com>
> >
> >Hello, Arend,
> >
> >Thank you for tracking this down!  Could you please try out the following
> >patch?
> 
> Thanks, Paul
> 
> That did the trick. Made me bumping into another regression in the
> driver I am maintaining so more fun to do :-)
> 
> Looking at the commit message I guess it is already in some tree.
> Otherwise I would have said: "You may add
> 
> Tested-by: Arend van Spriel <arend@broadcom.com>"

Thank you for trying it out, and glad that it worked for you!

And I did already send the pull request.  But if I need to re-send it,
I will update to add your Tested-by.

							Thanx, Paul

> >------------------------------------------------------------------------
> >
> >rcu: Fix comparison sense in rcu_needs_cpu()
> >
> >Commit c0f4dfd4f (rcu: Make RCU_FAST_NO_HZ take advantage of numbered
> >callbacks) introduced a bug that can result in excessively long grace
> >periods.  This bug reverse the senes of the "if" statement checking
> 
> Oh, there is a typo in the commit message: sense iso senes.
> 
> >for lazy callbacks, so that RCU takes a lazy approach when there are
> >in fact non-lazy callbacks.  This can result in excessive boot, suspend,
> >and resume times.
> >
> >This commit therefore fixes the sense of this "if" statement.
> >
> >Reported-by: Borislav Petkov<bp@alien8.de>
> >Reported-by: Bjørn Mork<bjorn@mork.no>
> >Reported-by: Joerg Roedel<joro@8bytes.org>
> >Signed-off-by: Paul E. McKenney<paulmck@linux.vnet.ibm.com>
> >Tested-by: Bjørn Mork<bjorn@mork.no>
> >Tested-by: Joerg Roedel<joro@8bytes.org>
> 
> Gr. AvS
>