[PATCH] powerpc: Fix bug where perf_counters breaks oprofile

[Josh Boyer]

On Tue, Sep 15, 2009 at 10:56:47AM +1000, Benjamin Herrenschmidt wrote:
>On Mon, 2009-09-14 at 16:43 -0400, Josh Boyer wrote:
>> On Mon, Sep 14, 2009 at 03:14:02PM -0500, Maynard Johnson wrote:
>> >Maynard Johnson wrote:
>> >> Paul Mackerras wrote:
>> >>> Currently there is a bug where if you use oprofile on a pSeries
>> >>> machine, then use perf_counters, then use oprofile again, oprofile
>> >>> will not work correctly; it will lose the PMU configuration the next
>> >>> time the hypervisor does a partition context switch, and thereafter
>> >>> won't count anything.
>> >Ben,
>> >Is there any way to get this bug fix into 2.6.31 or is the window closed?  Once the problem occurs, you can't get oprofile to work again without a reboot.  Really would be nice (for many reasons) to get this fixed in .31.
>> 
>> .31 is already released.  Could probably get it into a -stable .31 kernel
>> though.
>
>The fix is already upstream as well no ?

Sort of.  It's in your next branch, but not in Linus' tree.

Anyway, some people like to have particular versions work so -stable is good
regardless :).

josh