Merge branch 'perf/urgent' into perf/core, to pick up fixes before applying new changes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

4 files changed, 90 insertions, 38 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index a478e3c4cc3f..3f124d553c5a 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -2758,7 +2758,7 @@ static int intel_pmu_cpu_prepare(int cpu)
         if (x86_pmu.extra_regs || x86_pmu.lbr_sel_map) {
                 cpuc->shared_regs = allocate_shared_regs(cpu);
                 if (!cpuc->shared_regs)
-                        return NOTIFY_BAD;
+                        goto err;
         }
 
         if (x86_pmu.flags & PMU_FL_EXCL_CNTRS) {
@@ -2766,18 +2766,27 @@ static int intel_pmu_cpu_prepare(int cpu)
 
                 cpuc->constraint_list = kzalloc(sz, GFP_KERNEL);
                 if (!cpuc->constraint_list)
-                        return NOTIFY_BAD;
+                        goto err_shared_regs;
 
                 cpuc->excl_cntrs = allocate_excl_cntrs(cpu);
-                if (!cpuc->excl_cntrs) {
-                        kfree(cpuc->constraint_list);
-                        kfree(cpuc->shared_regs);
-                        return NOTIFY_BAD;
-                }
+                if (!cpuc->excl_cntrs)
+                        goto err_constraint_list;
+
                 cpuc->excl_thread_id = 0;
         }
 
         return NOTIFY_OK;
+
+err_constraint_list:
+        kfree(cpuc->constraint_list);
+        cpuc->constraint_list = NULL;
+
+err_shared_regs:
+        kfree(cpuc->shared_regs);
+        cpuc->shared_regs = NULL;
+
+err:
+        return NOTIFY_BAD;
 }
 
 static void intel_pmu_cpu_starting(int cpu)
diff --git a/arch/x86/kernel/cpu/perf_event_intel_cqm.c b/arch/x86/kernel/cpu/perf_event_intel_cqm.c
index 63eb68b73589..377e8f8ed391 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_cqm.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_cqm.c
@@ -1255,7 +1255,7 @@ static inline void cqm_pick_event_reader(int cpu)
         cpumask_set_cpu(cpu, &cqm_cpumask);
 }
 
-static void intel_cqm_cpu_prepare(unsigned int cpu)
+static void intel_cqm_cpu_starting(unsigned int cpu)
 {
         struct intel_pqr_state *state = &per_cpu(pqr_state, cpu);
         struct cpuinfo_x86 *c = &cpu_data(cpu);
@@ -1296,13 +1296,11 @@ static int intel_cqm_cpu_notifier(struct notifier_block *nb,
         unsigned int cpu  = (unsigned long)hcpu;
 
         switch (action & ~CPU_TASKS_FROZEN) {
-        case CPU_UP_PREPARE:
-                intel_cqm_cpu_prepare(cpu);
-                break;
         case CPU_DOWN_PREPARE:
                 intel_cqm_cpu_exit(cpu);
                 break;
         case CPU_STARTING:
+                intel_cqm_cpu_starting(cpu);
                 cqm_pick_event_reader(cpu);
                 break;
         }
@@ -1373,7 +1371,7 @@ static int __init intel_cqm_init(void)
                 goto out;
 
         for_each_online_cpu(i) {
-                intel_cqm_cpu_prepare(i);
+                intel_cqm_cpu_starting(i);
                 cqm_pick_event_reader(i);
         }
 
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 77f9e5d0e2d1..ae16867670a9 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3972,28 +3972,21 @@ static void perf_event_for_each(struct perf_event *event,
                 perf_event_for_each_child(sibling, func);
 }
 
-static int perf_event_period(struct perf_event *event, u64 __user *arg)
-{
-        struct perf_event_context *ctx = event->ctx;
-        int ret = 0, active;
+struct period_event {
+        struct perf_event *event;
         u64 value;
+};
 
-        if (!is_sampling_event(event))
-                return -EINVAL;
-
-        if (copy_from_user(&value, arg, sizeof(value)))
-                return -EFAULT;
-
-        if (!value)
-                return -EINVAL;
+static int __perf_event_period(void *info)
+{
+        struct period_event *pe = info;
+        struct perf_event *event = pe->event;
+        struct perf_event_context *ctx = event->ctx;
+        u64 value = pe->value;
+        bool active;
 
-        raw_spin_lock_irq(&ctx->lock);
+        raw_spin_lock(&ctx->lock);
         if (event->attr.freq) {
-                if (value > sysctl_perf_event_sample_rate) {
-                        ret = -EINVAL;
-                        goto unlock;
-                }
-
                 event->attr.sample_freq = value;
         } else {
                 event->attr.sample_period = value;
@@ -4012,11 +4005,53 @@ static int perf_event_period(struct perf_event *event, u64 __user *arg)
                 event->pmu->start(event, PERF_EF_RELOAD);
                 perf_pmu_enable(ctx->pmu);
         }
+        raw_spin_unlock(&ctx->lock);
 
-unlock:
+        return 0;
+}
+
+static int perf_event_period(struct perf_event *event, u64 __user *arg)
+{
+        struct period_event pe = { .event = event, };
+        struct perf_event_context *ctx = event->ctx;
+        struct task_struct *task;
+        u64 value;
+
+        if (!is_sampling_event(event))
+                return -EINVAL;
+
+        if (copy_from_user(&value, arg, sizeof(value)))
+                return -EFAULT;
+
+        if (!value)
+                return -EINVAL;
+
+        if (event->attr.freq && value > sysctl_perf_event_sample_rate)
+                return -EINVAL;
+
+        task = ctx->task;
+        pe.value = value;
+
+        if (!task) {
+                cpu_function_call(event->cpu, __perf_event_period, &pe);
+                return 0;
+        }
+
+retry:
+        if (!task_function_call(task, __perf_event_period, &pe))
+                return 0;
+
+        raw_spin_lock_irq(&ctx->lock);
+        if (ctx->is_active) {
+                raw_spin_unlock_irq(&ctx->lock);
+                task = ctx->task;
+                goto retry;
+        }
+
+        __perf_event_period(&pe);
         raw_spin_unlock_irq(&ctx->lock);
 
-        return ret;
+        return 0;
 }
 
 static const struct file_operations perf_fops;
@@ -4754,12 +4789,20 @@ static const struct file_operations perf_fops = {