Changeset 31d8e10 in mainline for kernel/generic/src/ipc/ipc.c

Timestamp:

2007-04-05T16:09:49Z (18 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

547fa39

Parents:

879585a3

Message:

Continue to de-oversynchronize the kernel.

• replace as→refcount with an atomic counter; accesses to this

reference counter are not to be done when the as→lock mutex is held;
this gets us rid of mutex_lock_active();

Remove the possibility of a deadlock between TLB shootdown and asidlock.

• get rid of mutex_lock_active() on as→lock
• when locking the asidlock spinlock, always do it conditionally and with

preemption disabled; in the unsuccessful case, enable interrupts and try again

• there should be no deadlock between TLB shootdown and the as→lock mutexes
• PLEASE REVIEW !!!

Add DEADLOCK_PROBE's to places where we have spinlock_trylock() loops.

File:

• kernel/generic/src/ipc/ipc.c (modified) (2 diffs)

kernel/generic/src/ipc/ipc.c

@@ -375 +375 @@
         call_t *call;
         phone_t *phone;
+        DEADLOCK_PROBE_INIT(p_phonelck);
 
         /* Disconnect all our phones ('ipc_phone_hangup') */
@@ -388 +389 @@
         while (!list_empty(&TASK->answerbox.connected_phones)) {
                 phone = list_get_instance(TASK->answerbox.connected_phones.next,
-                                          phone_t, link);
+                    phone_t, link);
                 if (! spinlock_trylock(&phone->lock)) {
                         spinlock_unlock(&TASK->answerbox.lock);
+                        DEADLOCK_PROBE(p_phonelck, DEADLOCK_THRESHOLD);
                         goto restart_phones;
                 }