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Commit 151a0eb6 authored by Hendrik Brueckner's avatar Hendrik Brueckner Committed by Martin Schwidefsky
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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: default avatarHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent bddb7ae2

arch/s390/kernel/perf_cpum_cf.c

+6 −7
Original line number Diff line number Diff line
@@ -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: