On Thu, Mar 14, 2019 at 6:11 AM Peter Zijlstra <[email protected]> wrote: > > There is a special case for validate_events() where we'll call > x86_pmu.get_constraints(.idx=-1). It's purpose, up until recent, seems > to be to avoid taking a previous constraint from > cpuc->event_constraint[] in intel_get_event_constraints(). > > (I could not find any other get_event_constraints() implementation > using @idx) > > However, since that cpuc is freshly allocated, that array will in fact > be initialized with NULL pointers, achieving the very same effect. > > Therefore remove this exception. > > Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Looks good to me. Reviewed-by: Stephane Eranian <[email protected]> > --- > arch/x86/events/core.c | 2 +- > arch/x86/events/intel/core.c | 8 +++----- > 2 files changed, 4 insertions(+), 6 deletions(-) > > --- a/arch/x86/events/core.c > +++ b/arch/x86/events/core.c > @@ -2031,7 +2031,7 @@ static int validate_event(struct perf_ev > if (IS_ERR(fake_cpuc)) > return PTR_ERR(fake_cpuc); > > - c = x86_pmu.get_event_constraints(fake_cpuc, -1, event); > + c = x86_pmu.get_event_constraints(fake_cpuc, 0, event); > > if (!c || !c->weight) > ret = -EINVAL; > --- a/arch/x86/events/intel/core.c > +++ b/arch/x86/events/intel/core.c > @@ -2931,11 +2931,9 @@ static struct event_constraint * > intel_get_event_constraints(struct cpu_hw_events *cpuc, int idx, > struct perf_event *event) > { > - struct event_constraint *c1 = NULL; > - struct event_constraint *c2; > + struct event_constraint *c1, *c2; > > - if (idx >= 0) /* fake does < 0 */ > - c1 = cpuc->event_constraint[idx]; > + c1 = cpuc->event_constraint[idx]; > > /* > * first time only > @@ -3410,7 +3408,7 @@ tfa_get_event_constraints(struct cpu_hw_ > /* > * Without TFA we must not use PMC3. > */ > - if (!allow_tsx_force_abort && test_bit(3, c->idxmsk) && idx >= 0) { > + if (!allow_tsx_force_abort && test_bit(3, c->idxmsk)) { > c = dyn_constraint(cpuc, c, idx); > c->idxmsk64 &= ~(1ULL << 3); > c->weight--; > >
