diff options
| author |   Hendrik Brueckner <brueckner@linux.vnet.ibm.com> | 2013-12-12 16:52:48 +0100 |
|---|---|---|
| committer |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-12-16 14:37:52 +0100 |
| commit | e28bb79d9935293a8eea5f3c771fde89db645ba7 (patch) | |
| tree | 0d552a218e87c70ca55b5b103b5ef2a71477d400 /arch/s390/kernel/perf_event.c | |
| parent | s390/perf: Improve PMU selection for PERF_COUNT_HW_CPU_CYCLES events (diff) | |
| download | linux-dev-e28bb79d9935293a8eea5f3c771fde89db645ba7.tar.xz linux-dev-e28bb79d9935293a8eea5f3c771fde89db645ba7.zip | |
s390/perf,oprofile: Share sampling facility
Introduce reserve/release functions to share the sampling facility
between perf and oprofile.
Also improve error handling for the sampling facility support in perf.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/perf_event.c')
| -rw-r--r-- | arch/s390/kernel/perf_event.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c index b9843ba9829f..4edcdfa4894e 100644 --- a/arch/s390/kernel/perf_event.c +++ b/arch/s390/kernel/perf_event.c @@ -208,3 +208,33 @@ ssize_t cpumf_events_sysfs_show(struct device *dev, return sprintf(page, "event=0x%04llx,name=%s\n", pmu_attr->id, attr->attr.name); } + +/* Reserve/release functions for sharing perf hardware */ +static DEFINE_SPINLOCK(perf_hw_owner_lock); +static void *perf_sampling_owner; + +int perf_reserve_sampling(void) +{ + int err; + + err = 0; + spin_lock(&perf_hw_owner_lock); + if (perf_sampling_owner) { + pr_warn("The sampling facility is already reserved by %p\n", + perf_sampling_owner); + err = -EBUSY; + } else + perf_sampling_owner = __builtin_return_address(0); + spin_unlock(&perf_hw_owner_lock); + return err; +} +EXPORT_SYMBOL(perf_reserve_sampling); + +void perf_release_sampling(void) +{ + spin_lock(&perf_hw_owner_lock); + WARN_ON(!perf_sampling_owner); + perf_sampling_owner = NULL; + spin_unlock(&perf_hw_owner_lock); +} +EXPORT_SYMBOL(perf_release_sampling); |