Changeset 31d8e10 in mainline for kernel/generic/src/time/timeout.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/time/timeout.c (modified) (3 diffs)

kernel/generic/src/time/timeout.c

@@ -45 +45 @@
 #include <arch/asm.h>
 #include <arch.h>
-
 
 /** Initialize timeouts
@@ -176 +175 @@
         link_t *l;
         ipl_t ipl;
+        DEADLOCK_PROBE_INIT(p_tolock);
 
 grab_locks:
@@ -187 +187 @@
         if (!spinlock_trylock(&t->cpu->timeoutlock)) {
                 spinlock_unlock(&t->lock);
-                interrupts_restore(ipl);                
+                interrupts_restore(ipl);
+                DEADLOCK_PROBE(p_tolock, DEADLOCK_THRESHOLD);
                 goto grab_locks;
         }