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perf, x86: P4 PMU - Introduce event alias feature

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Instead of hw_nmi_watchdog_set_attr() weak function
and appropriate x86_pmu::hw_watchdog_set_attr() call
we introduce even alias mechanism which allow us
to drop this routines completely and isolate quirks
of Netburst architecture inside P4 PMU code only.

The main idea remains the same though -- to allow
nmi-watchdog and perf top run simultaneously.

Note the aliasing mechanism applies to generic
PERF_COUNT_HW_CPU_CYCLES event only because arbitrary
event (say passed as RAW initially) might have some
additional bits set inside ESCR register changing
the behaviour of event and we can't guarantee anymore
that alias event will give the same result.

P.S. Thanks a huge to Don and Steven for for testing
     and early review.

Acked-by: Don Zickus <dzickus@redhat.com>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Stephane Eranian <eranian@google.com>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
CC: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20110708201712.GS23657@sun
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Cyrill Gorcunov
2011-07-09 00:17:12 +04:00
committed by Steven Rostedt
parent 4a9bd3f134
commit f912987097
4 changed files with 139 additions and 38 deletions
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7
arch/x86/kernel/cpu/perf_event.c
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@@ -274,7 +274,6 @@ struct x86_pmu {
void (*enable_all)(int added);
void (*enable)(struct perf_event *);
void (*disable)(struct perf_event *);
void (*hw_watchdog_set_attr)(struct perf_event_attr *attr);
int (*hw_config)(struct perf_event *event);
int (*schedule_events)(struct cpu_hw_events *cpuc, int n, int *assign);
unsigned eventsel;
@@ -360,12 +359,6 @@ static u64 __read_mostly hw_cache_extra_regs
[PERF_COUNT_HW_CACHE_OP_MAX]
[PERF_COUNT_HW_CACHE_RESULT_MAX];
void hw_nmi_watchdog_set_attr(struct perf_event_attr *wd_attr)
{
if (x86_pmu.hw_watchdog_set_attr)
x86_pmu.hw_watchdog_set_attr(wd_attr);
}
/*
* Propagate event elapsed time into the generic event.
* Can only be executed on the CPU where the event is active.