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authorHendrik Brueckner <brueckner@linux.vnet.ibm.com>2013-01-30 17:51:56 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2013-02-14 15:55:15 +0100
commit151a0eb6c8e4398f76453c791d8fd8f8167a7517 (patch)
treeffa9855aaab15c18a8f3e606b817c0341ed35283 /arch/s390/kernel/perf_cpum_cf.c
parentbddb7ae217cea0ef722468fce823f9e19a69c561 (diff)
downloadlinux-151a0eb6c8e4398f76453c791d8fd8f8167a7517.tar.bz2
s390/perf: cpum_cf: fallback to software sampling events
The CPU-measurement counter facility does not support sampling events and returns -EINVAL in that case. This return code lets the perf tool fail. To fall back to software sampling events, return -ENOENT instead. 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_cpum_cf.c')
-rw-r--r--arch/s390/kernel/perf_cpum_cf.c13
1 files changed, 6 insertions, 7 deletions
diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c
index 86ec7447e1f5..390d9ae57bb2 100644
--- a/arch/s390/kernel/perf_cpum_cf.c
+++ b/arch/s390/kernel/perf_cpum_cf.c
@@ -367,13 +367,6 @@ static int __hw_perf_event_init(struct perf_event *event)
if (ev >= PERF_CPUM_CF_MAX_CTR)
return -EINVAL;
- /* The CPU measurement counter facility does not have any interrupts
- * to do sampling. Sampling must be provided by external means,
- * for example, by timers.
- */
- if (hwc->sample_period)
- return -EINVAL;
-
/* Use the hardware perf event structure to store the counter number
* in 'config' member and the counter set to which the counter belongs
* in the 'config_base'. The counter set (config_base) is then used
@@ -418,6 +411,12 @@ static int cpumf_pmu_event_init(struct perf_event *event)
case PERF_TYPE_HARDWARE:
case PERF_TYPE_HW_CACHE:
case PERF_TYPE_RAW:
+ /* The CPU measurement counter facility does not have overflow
+ * interrupts to do sampling. Sampling must be provided by
+ * external means, for example, by timers.
+ */
+ if (is_sampling_event(event))
+ return -ENOENT;
err = __hw_perf_event_init(event);
break;
default: