Commit graph

58 commits

Author SHA1 Message Date
Peter Zijlstra
78f13e9525 perf_counter: allow for data addresses to be recorded
Paul suggested we allow for data addresses to be recorded along with
the traditional IPs as power can provide these.

For now, only the software pagefault events provide data addresses,
but in the future power might as well for some events.

x86 doesn't seem capable of providing this atm.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090408130409.394816925@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-08 19:05:56 +02:00
Peter Zijlstra
f6c7d5fe58 perf_counter: theres more to overflow than writing events
Prepare for more generic overflow handling. The new perf_counter_overflow()
method will handle the generic bits of the counter overflow, and can return
a !0 return value, in which case the counter should be (soft) disabled, so
that it won't count until it's properly disabled.

XXX: do powerpc and swcounter

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090406094517.812109629@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-07 10:48:56 +02:00
Peter Zijlstra
b6276f353b perf_counter: x86: self-IPI for pending work
Implement set_perf_counter_pending() with a self-IPI so that it will
run ASAP in a usable context.

For now use a second IRQ vector, because the primary vector pokes
the apic in funny ways that seem to confuse things.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090406094517.724626696@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-07 10:48:56 +02:00
Peter Zijlstra
5872bdb88a perf_counter: add more context information
Put in counts to tell which ips belong to what context.

  -----
   | |  hv
   | --
nr | |  kernel
   | --
   | |  user
  -----

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Orig-LKML-Reference: <20090402091319.493101305@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:30:46 +02:00
Peter Zijlstra
4e935e4717 perf_counter: pmc arbitration
Follow the example set by powerpc and try to play nice with oprofile
and the nmi watchdog.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171024.459968444@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:30:44 +02:00
Peter Zijlstra
d7d59fb323 perf_counter: x86: callchain support
Provide the x86 perf_callchain() implementation.

Code based on the ftrace/sysprof code from Soeren Sandmann Pedersen.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: Soeren Sandmann Pedersen <sandmann@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Orig-LKML-Reference: <20090330171024.341993293@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:30:43 +02:00
Peter Zijlstra
9ea98e1912 perf_counter: x86: proper error propagation for the x86 hw_perf_counter_init()
Now that Paul cleaned up the error propagation paths, pass down the
x86 error as well.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171023.792822360@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:30:40 +02:00
Peter Zijlstra
925d519ab8 perf_counter: unify and fix delayed counter wakeup
While going over the wakeup code I noticed delayed wakeups only work
for hardware counters but basically all software counters rely on
them.

This patch unifies and generalizes the delayed wakeup to fix this
issue.

Since we're dealing with NMI context bits here, use a cmpxchg() based
single link list implementation to track counters that have pending
wakeups.

[ This should really be generic code for delayed wakeups, but since we
  cannot use cmpxchg()/xchg() in generic code, I've let it live in the
  perf_counter code. -- Eric Dumazet could use it to aggregate the
  network wakeups. ]

Furthermore, the x86 method of using TIF flags was flawed in that its
quite possible to end up setting the bit on the idle task, loosing the
wakeup.

The powerpc method uses per-cpu storage and does appear to be
sufficient.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171023.153932974@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:30:36 +02:00
Peter Zijlstra
f4a2deb486 perf_counter: remove the event config bitfields
Since the bitfields turned into a bit of a mess, remove them and rely on
good old masks.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090323172417.059499915@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:30:25 +02:00
Peter Zijlstra
0322cd6ec5 perf_counter: unify irq output code
Impact: cleanup

Having 3 slightly different copies of the same code around does nobody
any good. First step in revamping the output format.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Orig-LKML-Reference: <20090319194233.929962222@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:30:17 +02:00
Peter Zijlstra
b8e83514b6 perf_counter: revamp syscall input ABI
Impact: modify ABI

The hardware/software classification in hw_event->type became a little
strained due to the addition of tracepoint tracing.

Instead split up the field and provide a type field to explicitly specify
the counter type, while using the event_id field to specify which event to
use.

Raw counters still work as before, only the raw config now goes into
raw_event.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Orig-LKML-Reference: <20090319194233.836807573@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:30:17 +02:00
Ingo Molnar
7bb497bd88 perf_counter: fix crash on perfmon v1 systems
Impact: fix boot crash on Intel Perfmon Version 1 systems

Intel Perfmon v1 does not support the global MSRs, nor does
it offer the generalized MSR ranges. So support v2 and later
CPUs only.

Also mark pmc_ops as read-mostly - to avoid false cacheline
sharing.

Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:30:14 +02:00
Peter Zijlstra
82bae4f8c2 perf_counter: x86: use ULL postfix for 64bit constants
Fix a build warning on 32bit machines by explicitly marking the
constants as 64-bit.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:29:34 +02:00
Peter Zijlstra
60b3df9c1e perf_counter: add comment to barrier
We need to ensure the enabled=0 write happens before we
start disabling the actual counters, so that a pcm_amd_enable()
will not enable one underneath us.

I think the race is impossible anyway, we always balance the
ops within any one context and perform enable() with IRQs disabled.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:29:32 +02:00
Peter Zijlstra
595258aaea perf_counter: x86: fix 32-bit irq_period assumption
No need to assume the irq_period is 32bit.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:29:29 +02:00
Jaswinder Singh Rajput
e255357764 x86: perf_counter cleanup
Remove unused variables and duplicate header file.

Signed-off-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-08 16:26:50 +01:00
Peter Zijlstra
184fe4ab1f x86: perf_counter cleanup
Use and actual unsigned long bitmap instead of casting our way around.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
LKML-Reference: <1236508459.22914.3645.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-08 16:24:49 +01:00
Peter Zijlstra
b5e8acf66f perfcounters: IRQ and NMI support on AMD CPUs, fix
The BKGD suggests that counter width on AMD CPUs is 48 for all
existing models (it certainly is for mine).

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-05 20:37:21 +01:00
Peter Zijlstra
b0f3f28e0f perfcounters: IRQ and NMI support on AMD CPUs
The below completes the K7+ performance counter support:

 - IRQ support
 - NMI support

KernelTop output works now as well.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1236273633.5187.286.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-05 18:25:16 +01:00
Jaswinder Singh Rajput
a1ef58f442 x86: use pr_info in perf_counter.c
Impact: cleanup

using pr_info in perf_counter.c fixes various 80 characters warnings and
also indenting for conditional statement

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 11:31:44 +01:00
Jaswinder Singh Rajput
169e41eb7f x86: decent declarations in perf_counter.c
Impact: cleanup

making decent declrations for struct pmc_x86_ops and
fix checkpatch error:
 ERROR: Macros with complex values should be enclosed in parenthesis

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 11:31:06 +01:00
Jaswinder Singh Rajput
f87ad35d37 x86: AMD Support for perf_counter
Supported basic performance counter for AMD K7 and later:

$ perfstat -e 0,1,2,3,4,5,-1,-2,-3,-4,-5 ls > /dev/null

 Performance counter stats for 'ls':

      12.298610  task clock ticks     (msecs)

        3298477  CPU cycles           (events)
        1406354  instructions         (events)
         749035  cache references     (events)
          16939  cache misses         (events)
         100589  branches             (events)
          11159  branch misses        (events)
       7.627540  cpu clock ticks      (msecs)
      12.298610  task clock ticks     (msecs)
            500  pagefaults           (events)
              6  context switches     (events)
              3  CPU migrations       (events)

 Wall-clock time elapsed:     8.672290 msecs

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-28 10:38:32 +01:00
Jaswinder Singh Rajput
b56a3802dc x86: prepare perf_counter to add more cpus
Introduced  struct pmc_x86_ops to add more cpus.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-28 10:38:27 +01:00
Paul Mackerras
0475f9ea8e perf_counters: allow users to count user, kernel and/or hypervisor events
Impact: new perf_counter feature

This extends the perf_counter_hw_event struct with bits that specify
that events in user, kernel and/or hypervisor mode should not be
counted (i.e. should be excluded), and adds code to program the PMU
mode selection bits accordingly on x86 and powerpc.

For software counters, we don't currently have the infrastructure to
distinguish which mode an event occurs in, so we currently fail the
counter initialization if the setting of the hw_event.exclude_* bits
would require us to distinguish.  Context switches and CPU migrations
are currently considered to occur in kernel mode.

On x86, this changes the previous policy that only root can count
kernel events.  Now non-root users can count kernel events or exclude
them.  Non-root users still can't use NMI events, though.  On x86 we
don't appear to have any way to control whether hypervisor events are
counted or not, so hw_event.exclude_hv is ignored.

On powerpc, the selection of whether to count events in user, kernel
and/or hypervisor mode is PMU-wide, not per-counter, so this adds a
check that the hw_event.exclude_* settings are the same as other events
on the PMU.  Counters being added to a group have to have the same
settings as the other hardware counters in the group.  Counters and
groups can only be enabled in hw_perf_group_sched_in or power_perf_enable
if they have the same settings as any other counters already on the
PMU.  If we are not running on a hypervisor, the exclude_hv setting
is ignored (by forcing it to 0) since we can't ever get any
hypervisor events.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-02-11 15:06:59 +11:00
Mike Galbraith
d278c48435 perf_counters: account NMI interrupts
I noticed that kerneltop interrupts were accounted as NMI, but not their
perf counter origin.

Account NMI performance counter interrupts.

Signed-off-by: Mike Galbraith  <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

 arch/x86/kernel/cpu/perf_counter.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
2009-02-09 13:03:38 +01:00
Mike Galbraith
5b75af0a02 perfcounters: fix "perf counters kill oprofile" bug
With oprofile as a module, and unloaded by profiling script,
both oprofile and kerneltop work fine.. unless you leave kerneltop
running when you start profiling, then you may see badness.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-04 17:36:18 +01:00
Mike Galbraith
3415dd9146 perfcounters fix section mismatch warning in perf_counter.c::perf_counters_lapic_init()
Fix:

WARNING: arch/x86/kernel/built-in.o(.text+0xdd0f): Section mismatch in reference from the function pmc_generic_enable() to the function .cpuinit.text:perf_counters_lapic_init()
The function pmc_generic_enable() references
the function __cpuinit perf_counters_lapic_init().
This is often because pmc_generic_enable lacks a __cpuinit
annotation or the annotation of perf_counters_lapic_init is wrong.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-23 14:51:22 +01:00
Mike Galbraith
4b39fd9685 perfcounters: ratelimit performance counter interrupts
Ratelimit performance counter interrupts to 100KHz per CPU.

This replaces the irq-delta-time based method.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-23 14:50:02 +01:00
Mike Galbraith
1b023a96d9 perfcounters: throttle on too high IRQ rates
Starting kerneltop with only -c 100 seems to be a bad idea, it can
easily lock the system due to perfcounter IRQ overload.

So add throttling: if a new IRQ arrives in a shorter than
PERFMON_MIN_PERIOD_NS time, turn off perfcounters and untrottle them
from the next timer tick.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-23 11:33:18 +01:00
Jaswinder Singh Rajput
2b583d8bc8 x86: perf_counter remove unwanted hw_perf_enable_all
Impact: clean, reduce kernel size a bit, avoid sparse warnings

Fixes sparse warnings:

 arch/x86/kernel/cpu/perf_counter.c:153:6: warning: symbol 'hw_perf_enable_all' was not declared. Should it be static?
 arch/x86/kernel/cpu/perf_counter.c:279:3: warning: returning void-valued expression
 arch/x86/kernel/cpu/perf_counter.c:206:3: warning: returning void-valued expression
 arch/x86/kernel/cpu/perf_counter.c:206:3: warning: returning void-valued expression

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-27 16:00:51 +01:00
Ingo Molnar
2f18d1e8d0 x86, perfcounters: add support for fixed-function pmcs
Impact: extend performance counter support on x86 Intel CPUs

Modern Intel CPUs have 3 "fixed-function" performance counters, which
count these hardware events:

    Instr_Retired.Any
    CPU_CLK_Unhalted.Core
    CPU_CLK_Unhalted.Ref

Add support for them to the performance counters subsystem.

Their use is transparent to user-space: the counter scheduler is
extended to automatically recognize the cases where a fixed-function
PMC can be utilized instead of a generic PMC. In such cases the
generic PMC is kept available for more counters.

The above fixed-function events map to these generic counter hw events:

        PERF_COUNT_INSTRUCTIONS
        PERF_COUNT_CPU_CYCLES
        PERF_COUNT_BUS_CYCLES

(The 'bus' cycles are in reality often CPU-ish cycles, just with a fixed
 frequency.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 12:45:25 +01:00
Ingo Molnar
f650a67235 perfcounters: add PERF_COUNT_BUS_CYCLES
Generalize "bus cycles" hw events - and map them to CPU_CLK_Unhalted.Ref
on x86. (which is a good enough approximation)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 12:45:24 +01:00
Ingo Molnar
0dff86aa7b x86, perfcounters: print out the ->used bitmask
Impact: extend debug printouts

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 12:45:20 +01:00
Ingo Molnar
95cdd2e785 perfcounters: enable lowlevel pmc code to schedule counters
Allow lowlevel ->enable() op to return an error if a counter can not be
added. This can be used to handle counter constraints.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 12:45:19 +01:00
Ingo Molnar
7671581f16 perfcounters: hw ops rename
Impact: rename field names

Shorten them.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 12:45:13 +01:00
Ingo Molnar
862a1a5f34 x86, perfcounters: refactor code for fixed-function PMCs
Impact: clean up

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 12:45:12 +01:00
Ingo Molnar
703e937c83 perfcounters: add fixed-mode PMC enumeration
Enumerate fixed-mode PMCs based on CPUID, and feed that into the
perfcounter code.

Does not use fixed-mode PMCs yet.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 12:45:11 +01:00
Ingo Molnar
eb2b861810 x86, perfcounters: prepare for fixed-mode PMCs
Impact: refactor the x86 code for fixed-mode PMCs

Extend the data structures and rename the existing facilities
to allow for a 'generic' versus 'fixed' counter distinction.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 12:45:10 +01:00
Ingo Molnar
5c167b8585 x86, perfcounters: rename intel_arch_perfmon.h => perf_counter.h
Impact: rename include file

We'll be providing an asm/perf_counter.h to the generic perfcounter code,
so use the already existing x86 file for this purpose and rename it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 12:45:09 +01:00
Ingo Molnar
8fb9331391 perfcounters: remove warnings
Impact: remove debug checks

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-23 12:45:08 +01:00
Jaswinder Singh
94c46572a6 x86: perf_counter.c intel_perfmon_event_map and max_intel_perfmon_events should be static
Impact: cleanup, avoid sparse warnings, reduce kernel size a bit

Fixes these sparse warnings:
 arch/x86/kernel/cpu/perf_counter.c:44:11: warning: symbol 'intel_perfmon_event_map' was not declared. Should it be static?
 arch/x86/kernel/cpu/perf_counter.c:54:11: warning: symbol 'max_intel_perfmon_events' was not declared. Should it be static?

Signed-off-by: Jaswinder Singh <jaswinder@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-19 23:15:10 +01:00
Ingo Molnar
75f224cf77 perfcounters: fix lapic initialization
Fix non-working NMI sampling in certain bootup scenarios.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-14 22:00:31 +01:00
Ingo Molnar
2b9ff0db19 perfcounters: fix non-intel-perfmon CPUs
Do not write MSR_CORE_PERF_GLOBAL_CTRL on CPUs where it does not exist.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-14 20:31:28 +01:00
Ingo Molnar
ee06094f82 perfcounters: restructure x86 counter math
Impact: restructure code

Change counter math from absolute values to clear delta logic.

We try to extract elapsed deltas from the raw hw counter - and put
that into the generic counter.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-14 20:30:48 +01:00
Ingo Molnar
92bf73e90a Merge branch 'x86/irq' into perfcounters/core
( with manual semantic merge of arch/x86/kernel/cpu/perf_counter.c )
2008-12-12 12:00:14 +01:00
Ingo Molnar
6a930700c8 perf counters: clean up state transitions
Impact: cleanup

Introduce a proper enum for the 3 states of a counter:

	PERF_COUNTER_STATE_OFF		= -1
	PERF_COUNTER_STATE_INACTIVE	=  0
	PERF_COUNTER_STATE_ACTIVE	=  1

and rename counter->active to counter->state and propagate the
changes everywhere.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-11 15:45:56 +01:00
Ingo Molnar
01b2838c42 perf counters: consolidate hw_perf save/restore APIs
Impact: cleanup

Rename them to better match up the usual IRQ disable/enable APIs:

 hw_perf_disable_all()  => hw_perf_save_disable()
 hw_perf_restore_ctrl() => hw_perf_restore()

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-11 15:45:53 +01:00
Ingo Molnar
5c92d12411 perf counters: implement PERF_COUNT_CPU_CLOCK
Impact: add new perf-counter type

The 'CPU clock' counter counts the amount of CPU clock time that is
elapsing, in nanoseconds. (regardless of how much of it the task is
spending on a CPU executing)

This counter type is a Linux kernel based abstraction, it is available
even if the hardware does not support native hardware performance counters.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-11 15:45:52 +01:00
Ingo Molnar
621a01eac8 perf counters: hw driver API
Impact: restructure code, introduce hw_ops driver abstraction

Introduce this abstraction to handle counter details:

 struct hw_perf_counter_ops {
	void (*hw_perf_counter_enable)	(struct perf_counter *counter);
	void (*hw_perf_counter_disable)	(struct perf_counter *counter);
	void (*hw_perf_counter_read)	(struct perf_counter *counter);
 };

This will be useful to support assymetric hw details, and it will also
be useful to implement "software counters". (Counters that count kernel
managed sw events such as pagefaults, context-switches, wall-clock time
or task-local time.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-11 15:45:51 +01:00
Ingo Molnar
04289bb989 perf counters: add support for group counters
Impact: add group counters

This patch adds the "counter groups" abstraction.

Groups of counters behave much like normal 'single' counters, with a
few semantic and behavioral extensions on top of that.

A counter group is created by creating a new counter with the open()
syscall's group-leader group_fd file descriptor parameter pointing
to another, already existing counter.

Groups of counters are scheduled in and out in one atomic group, and
they are also roundrobin-scheduled atomically.

Counters that are member of a group can also record events with an
(atomic) extended timestamp that extends to all members of the group,
if the record type is set to PERF_RECORD_GROUP.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-11 15:45:49 +01:00