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From: will.deacon@arm•com (Will Deacon)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 5/5] arm/perfevents: implement perf event support for	ARMv6
Date: Wed, 16 Dec 2009 11:04:09 -0000	[thread overview]
Message-ID: <000501ca7e3f$7e376740$7aa635c0$@deacon@arm.com> (raw)
In-Reply-To: <20091216105403.GX4141@wear.picochip.com>

*Jamie Iles wrote:

> > That's exactly what I do for single core ARMv6. However, in the list of events
> > for mpcore I can't see any that wouldn't count. There's plenty of reserved
> > identifiers though so hopefully one of those will do the job. Also, ARM
> > counters can't be set to exclude any modes.
>
> Thinking about this a bit more, although we can't disable the counters, we can
> disable their interrupt reporting. So, when the generic perf events layer
> calls pmu->disable(event), we do the update of the event then turn off the
> IRQ. When we come to unthrottling, the counter will have carried on counting,
> but if we set the period again, the counter gets set with the correct restart
> value and then reenabled.

This was my first thought, but I was concerned about how it would play out
with the armpmu_read function. Now that I see we don't read disabled counters,
I can't see any reason not to simply disable the interrupt and stash the count
value.
 
> I think this should work for mpcore and is also required for the cycle counter
> on all v6 cores. I've given this a go using an artificially low period on a
> cycle counter and it does appear to do the job.

If we do this for mpcore, is it worth doing the same thing for the other v6 cores
too [and removing the ETM `hack']?

Cheers,

Will

  reply	other threads:[~2009-12-16 11:04 UTC|newest]

Thread overview: 89+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-15 11:15 ARMv6 performance counters v3 Jamie Iles
2009-12-15 11:15 ` [PATCH 1/5] arm: provide a mechanism to reserve performance counters Jamie Iles
2009-12-15 11:15   ` [PATCH 2/5] arm/oprofile: reserve the PMU when starting Jamie Iles
2009-12-15 11:15     ` [PATCH 3/5] arm: use the spinlocked, generic atomic64 support Jamie Iles
2009-12-15 11:15       ` [PATCH 4/5] arm: enable support for software perf events Jamie Iles
2009-12-15 11:15         ` [PATCH 5/5] arm/perfevents: implement perf event support for ARMv6 Jamie Iles
2009-12-15 14:29           ` Will Deacon
2009-12-15 15:02             ` Jamie Iles
2009-12-15 15:05               ` Will Deacon
2009-12-15 15:19                 ` Jamie Iles
2009-12-15 15:30                   ` Peter Zijlstra
2009-12-15 15:36                     ` Jamie Iles
2009-12-16 10:54                       ` Jamie Iles
2009-12-16 11:04                         ` Will Deacon [this message]
2009-12-16 11:19                           ` Jamie Iles
2009-12-18 17:05           ` Perf Event support for ARMv7 (was: Re: [PATCH 5/5] arm/perfevents: implement perf event support for ARMv6) Jean Pihet
2009-12-19 10:29             ` Jamie Iles
2009-12-19 10:53               ` Ingo Molnar
2009-12-21 11:32                 ` Jean Pihet
2009-12-21 11:29               ` Jean Pihet
2009-12-21 11:04             ` Will Deacon
2009-12-21 11:43               ` Jean Pihet
2009-12-21 12:10                 ` Will Deacon
2009-12-21 12:43                   ` Jamie Iles
2009-12-21 13:35                     ` Jean Pihet
2009-12-22 16:51                       ` Jean Pihet
2009-12-28  7:57                         ` Ingo Molnar
2009-12-29 13:52                           ` Jean Pihet
2009-12-29 16:32                             ` Jamie Iles
2010-01-06 15:16                               ` Michał Nazarewicz
2010-01-06 15:30                                 ` Jamie Iles
2010-01-07 17:02                                   ` Michał Nazarewicz
2009-12-29 13:58                         ` Jean Pihet
2010-01-04 16:52                           ` Will Deacon
2010-01-15 15:30                             ` Jean Pihet
2010-01-15 15:39                               ` Jamie Iles
2010-01-15 15:43                                 ` Jean Pihet
2010-01-15 15:49                                   ` Jamie Iles
2010-01-20 13:40                               ` Will Deacon
2010-01-08 22:17                         ` Woodruff, Richard
2010-01-15 15:34                           ` Jean Pihet
2009-12-15 14:13   ` [PATCH 1/5] arm: provide a mechanism to reserve performance counters Will Deacon
2009-12-15 14:36     ` Jamie Iles
2009-12-15 17:06       ` Will Deacon
2009-12-17 16:14   ` Will Deacon
2009-12-17 16:27     ` Jamie Iles
  -- strict thread matches above, loose matches on Subject: below --
2010-01-14 12:14 ARM perf events support v5 Jamie Iles
2010-01-14 12:14 ` [PATCH 1/5] arm: provide a mechanism to reserve performance counters Jamie Iles
2010-01-14 12:14   ` [PATCH 2/5] arm/oprofile: reserve the PMU when starting Jamie Iles
2010-01-14 12:14     ` [PATCH 3/5] arm: use the spinlocked, generic atomic64 support Jamie Iles
2010-01-14 12:14       ` [PATCH 4/5] arm: enable support for software perf events Jamie Iles
2010-01-14 12:14         ` [PATCH 5/5] arm/perfevents: implement perf event support for ARMv6 Jamie Iles
2010-01-21  9:39           ` Jamie Iles
2010-01-21 10:28             ` Will Deacon
2010-01-21 10:37               ` Jamie Iles
2010-01-21 10:38             ` Russell King - ARM Linux
2010-01-21 10:56               ` Will Deacon
2010-01-21 12:21               ` Jean Pihet
2010-01-21 12:27                 ` Jamie Iles
2010-01-21 12:32                   ` Jean Pihet
2010-01-21 14:04                     ` Jamie Iles
2010-01-21 12:34                 ` Will Deacon
2010-01-21 12:42                   ` Jean Pihet
2010-01-22 15:25                     ` Will Deacon
2010-01-21 12:45                   ` Russell King - ARM Linux
2010-01-26 16:03                 ` Tomasz Fujak
2010-01-26 16:09                   ` Jamie Iles
2010-01-26 16:11                     ` Jean Pihet
2010-01-26 17:47                       ` Jean Pihet
2010-01-27 17:26                         ` Will Deacon
2010-01-27 17:40                           ` Jean Pihet
2010-01-27 17:57                             ` Will Deacon
2010-01-28 11:26                               ` Jamie Iles
2010-01-30 16:15                                 ` Russell King - ARM Linux
2010-02-02 17:14                                 ` Russell King - ARM Linux
2010-02-02 17:28                                   ` Jamie Iles
2010-01-04 10:48 ARM perf events support v4 Jamie Iles
2010-01-04 10:48 ` [PATCH 1/5] arm: provide a mechanism to reserve performance counters Jamie Iles
2010-01-04 10:48   ` [PATCH 2/5] arm/oprofile: reserve the PMU when starting Jamie Iles
2010-01-04 10:48     ` [PATCH 3/5] arm: use the spinlocked, generic atomic64 support Jamie Iles
2010-01-04 10:48       ` [PATCH 4/5] arm: enable support for software perf events Jamie Iles
2010-01-04 10:48         ` [PATCH 5/5] arm/perfevents: implement perf event support for ARMv6 Jamie Iles
2010-01-04 11:17           ` Russell King - ARM Linux
2010-01-04 11:46             ` Jamie Iles
2010-01-05 18:07           ` Will Deacon
2010-01-05 18:23             ` Jean Pihet
2010-01-05 22:26             ` Jamie Iles
2010-01-05 22:31               ` Russell King - ARM Linux
2010-01-06  0:18                 ` Jamie Iles
2010-01-06 12:09                   ` Will Deacon
2010-01-06 12:14                     ` Jamie Iles
2009-12-14 14:04 ARMv6 performance counters v2 Jamie Iles
2009-12-14 14:04 ` [PATCH 1/5] arm: provide a mechanism to reserve performance counters Jamie Iles
2009-12-14 14:04   ` [PATCH 2/5] arm/oprofile: reserve the PMU when starting Jamie Iles
2009-12-14 14:04     ` [PATCH 3/5] arm: use the spinlocked, generic atomic64 support Jamie Iles
2009-12-14 14:04       ` [PATCH 4/5] arm: enable support for software perf events Jamie Iles
2009-12-14 14:04         ` [PATCH 5/5] arm/perfevents: implement perf event support for ARMv6 Jamie Iles
2009-12-14 16:12           ` Jean Pihet
2009-12-14 16:33             ` Jamie Iles
2009-12-14 16:57               ` Jean Pihet
2009-12-14 17:09             ` Will Deacon
2009-12-14 16:13           ` Will Deacon
2009-12-14 16:20             ` Jamie Iles
2009-12-14 16:24               ` Will Deacon

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