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Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

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Pull perf fixes from Ingo Molnar:
 "These are the left over fixes from the v4.1 cycle"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf tools: Fix build breakage if prefix= is specified
  perf/x86: Honor the architectural performance monitoring version
  perf/x86/intel: Fix PMI handling for Intel PT
  perf/x86/intel/bts: Fix DS area sharing with x86_pmu events
  perf/x86: Add more Broadwell model numbers
  perf: Fix ring_buffer_attach() RCU sync, again
This commit is contained in:
Linus Torvalds
2015-06-22 15:45:41 -07:00
parent c58267e9fa 0f02adaa49
commit 6bc4c3ad36
6 changed files with 84 additions and 36 deletions
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71
arch/x86/kernel/cpu/perf_event.c
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@@ -135,6 +135,7 @@ static int x86_pmu_extra_regs(u64 config, struct perf_event *event)
}
static atomic_t active_events;
static atomic_t pmc_refcount;
static DEFINE_MUTEX(pmc_reserve_mutex);
#ifdef CONFIG_X86_LOCAL_APIC
@@ -270,11 +271,8 @@ msr_fail:
static void hw_perf_event_destroy(struct perf_event *event)
{
if (atomic_dec_and_mutex_lock(&active_events, &pmc_reserve_mutex)) {
release_pmc_hardware();
release_ds_buffers();
mutex_unlock(&pmc_reserve_mutex);
}
x86_release_hardware();
atomic_dec(&active_events);
}
void hw_perf_lbr_event_destroy(struct perf_event *event)
@@ -324,6 +322,35 @@ set_ext_hw_attr(struct hw_perf_event *hwc, struct perf_event *event)
return x86_pmu_extra_regs(val, event);
}
int x86_reserve_hardware(void)
{
int err = 0;
if (!atomic_inc_not_zero(&pmc_refcount)) {
mutex_lock(&pmc_reserve_mutex);
if (atomic_read(&pmc_refcount) == 0) {
if (!reserve_pmc_hardware())
err = -EBUSY;
else
reserve_ds_buffers();
}
if (!err)
atomic_inc(&pmc_refcount);
mutex_unlock(&pmc_reserve_mutex);
}
return err;
}
void x86_release_hardware(void)
{
if (atomic_dec_and_mutex_lock(&pmc_refcount, &pmc_reserve_mutex)) {
release_pmc_hardware();
release_ds_buffers();
mutex_unlock(&pmc_reserve_mutex);
}
}
/*
* Check if we can create event of a certain type (that no conflicting events
* are present).
@@ -336,21 +363,34 @@ int x86_add_exclusive(unsigned int what)
return 0;
mutex_lock(&pmc_reserve_mutex);
for (i = 0; i < ARRAY_SIZE(x86_pmu.lbr_exclusive); i++)
for (i = 0; i < ARRAY_SIZE(x86_pmu.lbr_exclusive); i++) {
if (i != what && atomic_read(&x86_pmu.lbr_exclusive[i]))
goto out;
}
atomic_inc(&x86_pmu.lbr_exclusive[what]);
ret = 0;
out:
mutex_unlock(&pmc_reserve_mutex);
/*
* Assuming that all exclusive events will share the PMI handler
* (which checks active_events for whether there is work to do),
* we can bump active_events counter right here, except for
* x86_lbr_exclusive_lbr events that go through x86_pmu_event_init()
* path, which already bumps active_events for them.
*/
if (!ret && what != x86_lbr_exclusive_lbr)
atomic_inc(&active_events);
return ret;
}
void x86_del_exclusive(unsigned int what)
{
atomic_dec(&x86_pmu.lbr_exclusive[what]);
atomic_dec(&active_events);
}
int x86_setup_perfctr(struct perf_event *event)
@@ -527,22 +567,11 @@ static int __x86_pmu_event_init(struct perf_event *event)
if (!x86_pmu_initialized())
return -ENODEV;
err = 0;
if (!atomic_inc_not_zero(&active_events)) {
mutex_lock(&pmc_reserve_mutex);
if (atomic_read(&active_events) == 0) {
if (!reserve_pmc_hardware())
err = -EBUSY;
else
reserve_ds_buffers();
}
if (!err)
atomic_inc(&active_events);
mutex_unlock(&pmc_reserve_mutex);
}
err = x86_reserve_hardware();
if (err)
return err;
atomic_inc(&active_events);
event->destroy = hw_perf_event_destroy;
event->hw.idx = -1;
@@ -1415,6 +1444,10 @@ perf_event_nmi_handler(unsigned int cmd, struct pt_regs *regs)
u64 finish_clock;
int ret;
/*
* All PMUs/events that share this PMI handler should make sure to
* increment active_events for their events.
*/
if (!atomic_read(&active_events))
return NMI_DONE;