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perf, x86: Remove checking_{wr,rd}msr() usage
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We don't need checking_{wr,rd}msr() calls, since we should know what cpu
we're running on and not use blindly poke at msrs.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Peter Zijlstra authored and Ingo Molnar committed Mar 10, 2010
1 parent b83a46e commit 7645a24
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Showing 2 changed files with 20 additions and 9 deletions.
24 changes: 18 additions & 6 deletions arch/x86/kernel/cpu/perf_event.c
Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,17 @@
#include <asm/stacktrace.h>
#include <asm/nmi.h>

#if 0
#undef wrmsrl
#define wrmsrl(msr, val) \
do { \
trace_printk("wrmsrl(%lx, %lx)\n", (unsigned long)(msr),\
(unsigned long)(val)); \
native_write_msr((msr), (u32)((u64)(val)), \
(u32)((u64)(val) >> 32)); \
} while (0)
#endif

/*
* best effort, GUP based copy_from_user() that assumes IRQ or NMI context
*/
Expand Down Expand Up @@ -821,14 +832,15 @@ void hw_perf_enable(void)

static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc)
{
(void)checking_wrmsrl(hwc->config_base + hwc->idx,
wrmsrl(hwc->config_base + hwc->idx,
hwc->config | ARCH_PERFMON_EVENTSEL_ENABLE);
}

static inline void x86_pmu_disable_event(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
(void)checking_wrmsrl(hwc->config_base + hwc->idx, hwc->config);

wrmsrl(hwc->config_base + hwc->idx, hwc->config);
}

static DEFINE_PER_CPU(u64 [X86_PMC_IDX_MAX], pmc_prev_left);
Expand All @@ -843,7 +855,7 @@ x86_perf_event_set_period(struct perf_event *event)
struct hw_perf_event *hwc = &event->hw;
s64 left = atomic64_read(&hwc->period_left);
s64 period = hwc->sample_period;
int err, ret = 0, idx = hwc->idx;
int ret = 0, idx = hwc->idx;

if (idx == X86_PMC_IDX_FIXED_BTS)
return 0;
Expand Down Expand Up @@ -881,8 +893,8 @@ x86_perf_event_set_period(struct perf_event *event)
*/
atomic64_set(&hwc->prev_count, (u64)-left);

err = checking_wrmsrl(hwc->event_base + idx,
(u64)(-left) & x86_pmu.event_mask);
wrmsrl(hwc->event_base + idx,
(u64)(-left) & x86_pmu.event_mask);

perf_event_update_userpage(event);

Expand Down Expand Up @@ -987,7 +999,7 @@ void perf_event_print_debug(void)
pr_info("CPU#%d: fixed: %016llx\n", cpu, fixed);
pr_info("CPU#%d: pebs: %016llx\n", cpu, pebs);
}
pr_info("CPU#%d: active: %016llx\n", cpu, *(u64 *)cpuc->active_mask);
pr_info("CPU#%d: active: %016llx\n", cpu, *(u64 *)cpuc->active_mask);

for (idx = 0; idx < x86_pmu.num_events; idx++) {
rdmsrl(x86_pmu.eventsel + idx, pmc_ctrl);
Expand Down
5 changes: 2 additions & 3 deletions arch/x86/kernel/cpu/perf_event_intel.c
Original file line number Diff line number Diff line change
Expand Up @@ -525,7 +525,7 @@ static void intel_pmu_disable_fixed(struct hw_perf_event *hwc)

rdmsrl(hwc->config_base, ctrl_val);
ctrl_val &= ~mask;
(void)checking_wrmsrl(hwc->config_base, ctrl_val);
wrmsrl(hwc->config_base, ctrl_val);
}

static void intel_pmu_disable_event(struct perf_event *event)
Expand Down Expand Up @@ -553,7 +553,6 @@ static void intel_pmu_enable_fixed(struct hw_perf_event *hwc)
{
int idx = hwc->idx - X86_PMC_IDX_FIXED;
u64 ctrl_val, bits, mask;
int err;

/*
* Enable IRQ generation (0x8),
Expand All @@ -578,7 +577,7 @@ static void intel_pmu_enable_fixed(struct hw_perf_event *hwc)
rdmsrl(hwc->config_base, ctrl_val);
ctrl_val &= ~mask;
ctrl_val |= bits;
err = checking_wrmsrl(hwc->config_base, ctrl_val);
wrmsrl(hwc->config_base, ctrl_val);
}

static void intel_pmu_enable_event(struct perf_event *event)
Expand Down

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