Commit 21d65555 authored Mar 14, 2019 by Peter Zijlstra Committed by Ingo Molnar Apr 03, 2019

perf/x86: Simplify x86_pmu.get_constraints() interface



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) <peterz@infradead.org>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 1a81542a

arch/x86/events/core.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2031,7 +2031,7 @@ static int validate_event(struct perf_event *event)
		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;

arch/x86/events/intel/core.c

+3 −5

Original line number	Diff line number	Diff line
		@@ -2931,10 +2931,8 @@ 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];

		/*
		@@ -3410,7 +3408,7 @@ tfa_get_event_constraints(struct cpu_hw_events *cpuc, int idx,
		/*
		* 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--;

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