perf/x86: Reduce stack usage of x86_schedule_events()

[karo-tx-linux.git] / arch / x86 / kernel / cpu / perf_event.c

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 1025f3c99d2065167b0b1484fb5410829344b7f1..e52a9e57778319a2f1098fab588d4cc8011c1496 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -568,7 +568,7 @@ struct sched_state {
 struct perf_sched {
        int                     max_weight;
        int                     max_events;
-       struct event_constraint **constraints;
+       struct perf_event       **events;
        struct sched_state      state;
        int                     saved_states;
        struct sched_state      saved[SCHED_STATES_MAX];
@@ -577,7 +577,7 @@ struct perf_sched {
 /*
  * Initialize interator that runs through all events and counters.
  */
-static void perf_sched_init(struct perf_sched *sched, struct event_constraint **c,
+static void perf_sched_init(struct perf_sched *sched, struct perf_event **events,
                            int num, int wmin, int wmax)
 {
        int idx;
@@ -585,10 +585,10 @@ static void perf_sched_init(struct perf_sched *sched, struct event_constraint **
        memset(sched, 0, sizeof(*sched));
        sched->max_events       = num;
        sched->max_weight       = wmax;
-       sched->constraints      = c;
+       sched->events           = events;
 
        for (idx = 0; idx < num; idx++) {
-               if (c[idx]->weight == wmin)
+               if (events[idx]->hw.constraint->weight == wmin)
                        break;
        }
 
@@ -635,8 +635,7 @@ static bool __perf_sched_find_counter(struct perf_sched *sched)
        if (sched->state.event >= sched->max_events)
                return false;
 
-       c = sched->constraints[sched->state.event];
-
+       c = sched->events[sched->state.event]->hw.constraint;
        /* Prefer fixed purpose counters */
        if (c->idxmsk64 & (~0ULL << INTEL_PMC_IDX_FIXED)) {
                idx = INTEL_PMC_IDX_FIXED;
@@ -694,7 +693,7 @@ static bool perf_sched_next_event(struct perf_sched *sched)
                        if (sched->state.weight > sched->max_weight)
                                return false;
                }
-               c = sched->constraints[sched->state.event];
+               c = sched->events[sched->state.event]->hw.constraint;
        } while (c->weight != sched->state.weight);
 
        sched->state.counter = 0;       /* start with first counter */
@@ -705,12 +704,12 @@ static bool perf_sched_next_event(struct perf_sched *sched)
 /*
  * Assign a counter for each event.
  */
-int perf_assign_events(struct event_constraint **constraints, int n,
+int perf_assign_events(struct perf_event **events, int n,
                        int wmin, int wmax, int *assign)
 {
        struct perf_sched sched;
 
-       perf_sched_init(&sched, constraints, n, wmin, wmax);
+       perf_sched_init(&sched, events, n, wmin, wmax);
 
        do {
                if (!perf_sched_find_counter(&sched))
@@ -724,7 +723,7 @@ int perf_assign_events(struct event_constraint **constraints, int n,
 
 int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 {
-       struct event_constraint *c, *constraints[X86_PMC_IDX_MAX];
+       struct event_constraint *c;
        unsigned long used_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
        int i, wmin, wmax, num = 0;
        struct hw_perf_event *hwc;
@@ -732,8 +731,10 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
        bitmap_zero(used_mask, X86_PMC_IDX_MAX);
 
        for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) {
+               hwc = &cpuc->event_list[i]->hw;
                c = x86_pmu.get_event_constraints(cpuc, cpuc->event_list[i]);
-               constraints[i] = c;
+               hwc->constraint = c;
+
                wmin = min(wmin, c->weight);
                wmax = max(wmax, c->weight);
        }
@@ -743,7 +744,7 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
         */
        for (i = 0; i < n; i++) {
                hwc = &cpuc->event_list[i]->hw;
-               c = constraints[i];
+               c = hwc->constraint;
 
                /* never assigned */
                if (hwc->idx == -1)
@@ -764,7 +765,8 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
 
        /* slow path */
        if (i != n)
-               num = perf_assign_events(constraints, n, wmin, wmax, assign);
+               num = perf_assign_events(cpuc->event_list, n, wmin,
+                                        wmax, assign);
 
        /*
         * scheduling failed or is just a simulation,