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s390/cpum_sf: Set bit PMU_F_ENABLED enabled after lpp() invocation 

Set PMU enabled bit after lpp() call. This ensures the proper
task PID is loaded by the llp instruction into Program Parameter
register from where it is copied to each sampling data buffer
(SDB) sample entry after the sampling was enabled.

The barrier() instruction is not needed as cpumsf_pmu_enable()
changes a CPU specific variable. Only the CPU that task is
running on changes structure members.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
pull/1083/head
Thomas Richter 2024-10-07 07:45:16 +02:00 committed by Heiko Carstens
parent 25f39d3dcb
commit 31d1d8a35e
1 changed files with 1 additions and 4 deletions
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5
arch/s390/kernel/perf_cpum_sf.c
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@ -942,18 +942,15 @@ static void cpumsf_pmu_enable(struct pmu *pmu)
}
/* (Re)enable the PMU and sampling facility */
cpuhw->flags |= PMU_F_ENABLED;
barrier();
err = lsctl(&cpuhw->lsctl);
if (err) {
cpuhw->flags &= ~PMU_F_ENABLED;
pr_err("Loading sampling controls failed: op 1 err %i\n", err);
return;
}
/* Load current program parameter */
lpp(&get_lowcore()->lpp);
cpuhw->flags |= PMU_F_ENABLED;
}
static void cpumsf_pmu_disable(struct pmu *pmu)