On 07/26/2013 11:31 AM, Will Deacon wrote:
> Hi Maynard,
> On Thu, Jul 25, 2013 at 08:37:28PM +0100, Maynard Johnson wrote:
>> On 07/25/2013 10:07 AM, Maynard Johnson wrote:
>>> On 07/24/2013 05:48 PM, Andi Kleen wrote:
>>>> From: Andi Kleen <ak@...>
>>>> Thanks to Sanjay Patel for noticing the missing ULT number.
>>> OK, Andi, I'll put out an RC2 that has this fix (I know of at least one other problem that should be fixed, too). Before rolling out RC2, I would like to get some more testing feedback on RC1 -- from any community members, but especially from my fellow maintainers on cc.
>> Oops! Didn't mean to leave you out of the fun, Will. ;-)
> Ok, all looks good on ARM (Cortex-A15) except that the minimum event period
> for the default event (CPU_CYCLES) is too low, so running operf -g without
> any additional arguments grinds everything to a halt.
> There's a patch below to sort that out.
Thanks for the ARM testing, Will.
*ATTENTION oprofile community*: So far, there are only three small changes to make in the 0.9.9-rc1:
- New model number of Haswell
- ocount fix for ppc64 events that have "GRP" in the name
- The ARM CPU_CYCLES default count value
I'm considering committing these changes and going straight to 0.9.9 GA, probably early next week. I encourage one and all to try out the RC1 as soon as possible and let me know if you have any concerns.
> From f0b0b77abebfe213954366e416efbe753647dc82 Mon Sep 17 00:00:00 2001
> From: Will Deacon <will.deacon@...>
> Date: Fri, 26 Jul 2013 17:26:07 +0100
> Subject: [PATCH] ARM: events: increase minimum cycle period to 100k
> On ARM, we intentionally leave the minimum event counters low since
> the performance profile of the cores can vary dramatically between CPUs
> and their implementations.
> However, since the default event is CPU_CYCLES, it's best to err on the
> side of caution and raise the limit to something more realistic so we
> don't lock-up on the unsuspecting user (as opposed to somebody passing
> an explicit event period).
> This patch raises the CPU_CYCLES minimum event count to 100k on ARM.
> Signed-off-by: Will Deacon <will.deacon@...>
> events/arm/armv7-common/events | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> diff --git a/events/arm/armv7-common/events b/events/arm/armv7-common/events
> index 0b6ed45..c83b2b7 100644
> --- a/events/arm/armv7-common/events
> +++ b/events/arm/armv7-common/events
> @@ -33,4 +33,4 @@ event:0x1B counters:1,2,3,4,5,6 um:zero minimum:500 name:INST_SPEC : Instruction
> event:0x1C counters:1,2,3,4,5,6 um:zero minimum:500 name:TTBR_WRITE_RETIRED : Write to TTBR architecturally executed, condition code pass
> event:0x1D counters:1,2,3,4,5,6 um:zero minimum:500 name:BUS_CYCLES : Bus cycle
> -event:0xFF counters:0 um:zero minimum:500 name:CPU_CYCLES : CPU cycle
> +event:0xFF counters:0 um:zero minimum:100000 name:CPU_CYCLES : CPU cycle