kern/thread: new thread_cpu function

2 files changed, 16 insertions, 0 deletions

diff --git a/kern/thread.c b/kern/thread.c
index 79199a8f..3b6ed3a0 100644
--- a/kern/thread.c
+++ b/kern/thread.c
@@ -2908,6 +2908,15 @@ thread_key_create(unsigned int *keyp, thread_dtor_fn_t dtor)
 }
 
 unsigned int
+thread_cpu(const struct thread *thread)
+{
+    const struct thread_runq *runq;
+
+    runq = atomic_load(&thread->runq, ATOMIC_RELAXED);
+    return runq->cpu;
+}
+
+unsigned int
 thread_state(const struct thread *thread)
 {
     return atomic_load(&thread->state, ATOMIC_RELAXED);
diff --git a/kern/thread.h b/kern/thread.h
index cc1a8a2b..38ee29b3 100644
--- a/kern/thread.h
+++ b/kern/thread.h
@@ -713,6 +713,13 @@ thread_get_specific(unsigned int key)
 }
 
 /*
+ * Return the last CPU on which the thread has been scheduled.
+ *
+ * This call isn't synchronized, and the caller may obtain an outdated value.
+ */
+unsigned int thread_cpu(const struct thread *thread);
+
+/*
  * Return the current state of the given thread.
  *
  * This call isn't synchronized, and the caller may obtain an outdated value.