Changeset c7326f21 in mainline for kernel/generic/src/proc/thread.c

Timestamp:

2023-02-25T11:51:04Z (14 months ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

master, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

4f84ee42

Parents:

4777e02

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2023-02-22 12:09:47)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2023-02-25 11:51:04)

Message:

Move some oddly placed accounting code

Thread ucycles and kcycles should be transferred to the task
accounting when a thread is destroyed, regardless of the
circumstances of its exit. The original code seems to only
do so when a thread returns from its implementing function.

File:

• kernel/generic/src/proc/thread.c (modified) (3 diffs)

kernel/generic/src/proc/thread.c

@@ -135 +135 @@
         f(arg);
 
-        /* Accumulate accounting to the task */
-        irq_spinlock_lock(&THREAD->lock, true);
-        if (!THREAD->uncounted) {
-                thread_update_accounting(true);
-                uint64_t ucycles = THREAD->ucycles;
-                THREAD->ucycles = 0;
-                uint64_t kcycles = THREAD->kcycles;
-                THREAD->kcycles = 0;
-
-                irq_spinlock_pass(&THREAD->lock, &TASK->lock);
-                TASK->ucycles += ucycles;
-                TASK->kcycles += kcycles;
-                irq_spinlock_unlock(&TASK->lock, true);
-        } else
-                irq_spinlock_unlock(&THREAD->lock, true);
-
         thread_exit();
 
@@ -419 +403 @@
         ipl_t ipl = interrupts_disable();
 
-        /* Remove thread from task's list. */
-        irq_spinlock_lock(&thread->task->lock, false);
-        list_remove(&thread->th_link);
-        irq_spinlock_unlock(&thread->task->lock, false);
-
         /* Remove thread from global list. */
         irq_spinlock_lock(&threads_lock, false);
@@ -429 +408 @@
         irq_spinlock_unlock(&threads_lock, false);
 
-        /* Clear cpu->fpu_owner if set to this thread. */
-        irq_spinlock_lock(&thread->lock, false);
+        /* Remove thread from task's list and accumulate accounting. */
+        irq_spinlock_lock(&thread->task->lock, false);
+
+        list_remove(&thread->th_link);
+
+        /*
+         * No other CPU has access to this thread anymore, so we don't need
+         * thread->lock for accessing thread's fields after this point.
+         */
+
+        if (!thread->uncounted) {
+                thread->task->ucycles += thread->ucycles;
+                thread->task->kcycles += thread->kcycles;
+        }
+
+        irq_spinlock_unlock(&thread->task->lock, false);
 
         assert((thread->state == Exiting) || (thread->state == Lingering));
         assert(thread->cpu);
 
+        /* Clear cpu->fpu_owner if set to this thread. */
         irq_spinlock_lock(&thread->cpu->lock, false);
         if (thread->cpu->fpu_owner == thread)
                 thread->cpu->fpu_owner = NULL;
         irq_spinlock_unlock(&thread->cpu->lock, false);
-
-        irq_spinlock_unlock(&thread->lock, false);
 
         interrupts_restore(ipl);