perf: Allow pinned and flexible groups to be scheduled separately

Tune the scheduling helpers so that we can choose to schedule either
pinned and/or flexible groups from a context.

And while at it, refactor a bit the naming of these helpers to make
these more consistent and flexible.

There is no (intended) change in scheduling behaviour in this
patch.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index c4e90b8..bfc4ee0 100644 (file)
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -1049,8 +1049,15 @@ static int perf_event_refresh(struct perf_event *event, int refresh)
        return 0;
 }
 
-static void __perf_event_sched_out(struct perf_event_context *ctx,
-                                  struct perf_cpu_context *cpuctx)
+enum event_type_t {
+       EVENT_FLEXIBLE = 0x1,
+       EVENT_PINNED = 0x2,
+       EVENT_ALL = EVENT_FLEXIBLE | EVENT_PINNED,
+};
+
+static void ctx_sched_out(struct perf_event_context *ctx,
+                         struct perf_cpu_context *cpuctx,
+                         enum event_type_t event_type)
 {
        struct perf_event *event;
 
@@ -1061,13 +1068,18 @@ static void __perf_event_sched_out(struct perf_event_context *ctx,
        update_context_time(ctx);
 
        perf_disable();
-       if (ctx->nr_active) {
+       if (!ctx->nr_active)
+               goto out_enable;
+
+       if (event_type & EVENT_PINNED)
                list_for_each_entry(event, &ctx->pinned_groups, group_entry)
                        group_sched_out(event, cpuctx, ctx);
 
+       if (event_type & EVENT_FLEXIBLE)
                list_for_each_entry(event, &ctx->flexible_groups, group_entry)
                        group_sched_out(event, cpuctx, ctx);
-       }
+
+ out_enable:
        perf_enable();
  out:
        raw_spin_unlock(&ctx->lock);
@@ -1229,15 +1241,13 @@ void perf_event_task_sched_out(struct task_struct *task,
        rcu_read_unlock();
 
        if (do_switch) {
-               __perf_event_sched_out(ctx, cpuctx);
+               ctx_sched_out(ctx, cpuctx, EVENT_ALL);
                cpuctx->task_ctx = NULL;
        }
 }
 
-/*
- * Called with IRQs disabled
- */
-static void __perf_event_task_sched_out(struct perf_event_context *ctx)
+static void task_ctx_sched_out(struct perf_event_context *ctx,
+                              enum event_type_t event_type)
 {
        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
 
@@ -1247,39 +1257,34 @@ static void __perf_event_task_sched_out(struct perf_event_context *ctx)
        if (WARN_ON_ONCE(ctx != cpuctx->task_ctx))
                return;
 
-       __perf_event_sched_out(ctx, cpuctx);
+       ctx_sched_out(ctx, cpuctx, event_type);
        cpuctx->task_ctx = NULL;
 }
 
 /*
  * Called with IRQs disabled
  */
-static void perf_event_cpu_sched_out(struct perf_cpu_context *cpuctx)
+static void __perf_event_task_sched_out(struct perf_event_context *ctx)
 {
-       __perf_event_sched_out(&cpuctx->ctx, cpuctx);
+       task_ctx_sched_out(ctx, EVENT_ALL);
+}
+
+/*
+ * Called with IRQs disabled
+ */
+static void cpu_ctx_sched_out(struct perf_cpu_context *cpuctx,
+                             enum event_type_t event_type)
+{
+       ctx_sched_out(&cpuctx->ctx, cpuctx, event_type);
 }
 
 static void
-__perf_event_sched_in(struct perf_event_context *ctx,
-                       struct perf_cpu_context *cpuctx)
+ctx_pinned_sched_in(struct perf_event_context *ctx,
+                   struct perf_cpu_context *cpuctx,
+                   int cpu)
 {
-       int cpu = smp_processor_id();
        struct perf_event *event;
-       int can_add_hw = 1;
-
-       raw_spin_lock(&ctx->lock);
-       ctx->is_active = 1;
-       if (likely(!ctx->nr_events))
-               goto out;
-
-       ctx->timestamp = perf_clock();
-
-       perf_disable();
 
-       /*
-        * First go through the list and put on any pinned groups
-        * in order to give them the best chance of going on.
-        */
        list_for_each_entry(event, &ctx->pinned_groups, group_entry) {
                if (event->state <= PERF_EVENT_STATE_OFF)
                        continue;
@@ -1298,6 +1303,15 @@ __perf_event_sched_in(struct perf_event_context *ctx,
                        event->state = PERF_EVENT_STATE_ERROR;
                }
        }
+}
+
+static void
+ctx_flexible_sched_in(struct perf_event_context *ctx,
+                     struct perf_cpu_context *cpuctx,
+                     int cpu)
+{
+       struct perf_event *event;
+       int can_add_hw = 1;
 
        list_for_each_entry(event, &ctx->flexible_groups, group_entry) {
                /* Ignore events in OFF or ERROR state */
@@ -1314,11 +1328,53 @@ __perf_event_sched_in(struct perf_event_context *ctx,
                        if (group_sched_in(event, cpuctx, ctx, cpu))
                                can_add_hw = 0;
        }
+}
+
+static void
+ctx_sched_in(struct perf_event_context *ctx,
+            struct perf_cpu_context *cpuctx,
+            enum event_type_t event_type)
+{
+       int cpu = smp_processor_id();
+
+       raw_spin_lock(&ctx->lock);
+       ctx->is_active = 1;
+       if (likely(!ctx->nr_events))
+               goto out;
+
+       ctx->timestamp = perf_clock();
+
+       perf_disable();
+
+       /*
+        * First go through the list and put on any pinned groups
+        * in order to give them the best chance of going on.
+        */
+       if (event_type & EVENT_PINNED)
+               ctx_pinned_sched_in(ctx, cpuctx, cpu);
+
+       /* Then walk through the lower prio flexible groups */
+       if (event_type & EVENT_FLEXIBLE)
+               ctx_flexible_sched_in(ctx, cpuctx, cpu);
+
        perf_enable();
  out:
        raw_spin_unlock(&ctx->lock);
 }
 
+static void task_ctx_sched_in(struct task_struct *task,
+                             enum event_type_t event_type)
+{
+       struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
+       struct perf_event_context *ctx = task->perf_event_ctxp;
+
+       if (likely(!ctx))
+               return;
+       if (cpuctx->task_ctx == ctx)
+               return;
+       ctx_sched_in(ctx, cpuctx, event_type);
+       cpuctx->task_ctx = ctx;
+}
 /*
  * Called from scheduler to add the events of the current task
  * with interrupts disabled.
@@ -1332,22 +1388,15 @@ __perf_event_sched_in(struct perf_event_context *ctx,
  */
 void perf_event_task_sched_in(struct task_struct *task)
 {
-       struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
-       struct perf_event_context *ctx = task->perf_event_ctxp;
-
-       if (likely(!ctx))
-               return;
-       if (cpuctx->task_ctx == ctx)
-               return;
-       __perf_event_sched_in(ctx, cpuctx);
-       cpuctx->task_ctx = ctx;
+       task_ctx_sched_in(task, EVENT_ALL);
 }
 
-static void perf_event_cpu_sched_in(struct perf_cpu_context *cpuctx)
+static void cpu_ctx_sched_in(struct perf_cpu_context *cpuctx,
+                            enum event_type_t event_type)
 {
        struct perf_event_context *ctx = &cpuctx->ctx;
 
-       __perf_event_sched_in(ctx, cpuctx);
+       ctx_sched_in(ctx, cpuctx, event_type);
 }
 
 #define MAX_INTERRUPTS (~0ULL)
@@ -1476,17 +1525,17 @@ void perf_event_task_tick(struct task_struct *curr)
        if (ctx)
                perf_ctx_adjust_freq(ctx);
 
-       perf_event_cpu_sched_out(cpuctx);
+       cpu_ctx_sched_out(cpuctx, EVENT_ALL);
        if (ctx)
-               __perf_event_task_sched_out(ctx);
+               task_ctx_sched_out(ctx, EVENT_ALL);
 
        rotate_ctx(&cpuctx->ctx);
        if (ctx)
                rotate_ctx(ctx);
 
-       perf_event_cpu_sched_in(cpuctx);
+       cpu_ctx_sched_in(cpuctx, EVENT_ALL);
        if (ctx)
-               perf_event_task_sched_in(curr);
+               task_ctx_sched_in(curr, EVENT_ALL);
 }
 
 static int event_enable_on_exec(struct perf_event *event,