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Commit 151a0eb6c8e4398f76453c791d8fd8f8167a7517

Authored by Hendrik Brueckner
Committed by Martin Schwidefsky
1 parent bddb7ae217
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

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>

Showing 1 changed file with 6 additions and 7 deletions Side-by-side Diff

arch/s390/kernel/perf_cpum_cf.c
Diff comments   View file @ 151a0eb
... ... @@ -367,13 +367,6 @@
367 367 if (ev >= PERF_CPUM_CF_MAX_CTR)
368 368 return -EINVAL;
369 369  
370   - /* The CPU measurement counter facility does not have any interrupts
371   - * to do sampling. Sampling must be provided by external means,
372   - * for example, by timers.
373   - */
374   - if (hwc->sample_period)
375   - return -EINVAL;
376   -
377 370 /* Use the hardware perf event structure to store the counter number
378 371 * in 'config' member and the counter set to which the counter belongs
379 372 * in the 'config_base'. The counter set (config_base) is then used
... ... @@ -418,6 +411,12 @@
418 411 case PERF_TYPE_HARDWARE:
419 412 case PERF_TYPE_HW_CACHE:
420 413 case PERF_TYPE_RAW:
  414 + /* The CPU measurement counter facility does not have overflow
  415 + * interrupts to do sampling. Sampling must be provided by
  416 + * external means, for example, by timers.
  417 + */
  418 + if (is_sampling_event(event))
  419 + return -ENOENT;
421 420 err = __hw_perf_event_init(event);
422 421 break;
423 422 default: