Pull sn2-mmio-writes into release branch

[linux-2.6-omap-h63xx.git] / include / asm-ia64 / system.h

diff --git a/include/asm-ia64/system.h b/include/asm-ia64/system.h
index 99b6f307e94bbb815e3d36ff458d717ec92857fb..cd4233d66f15ba1746f0ee94049ded722a887114 100644 (file)
--- a/include/asm-ia64/system.h
+++ b/include/asm-ia64/system.h
@@ -256,32 +256,7 @@ extern void ia64_load_extra (struct task_struct *task);
 # define switch_to(prev,next,last)     __switch_to(prev, next, last)
 #endif
 
-/*
- * On IA-64, we don't want to hold the runqueue's lock during the low-level context-switch,
- * because that could cause a deadlock.  Here is an example by Erich Focht:
- *
- * Example:
- * CPU#0:
- * schedule()
- *    -> spin_lock_irq(&rq->lock)
- *    -> context_switch()
- *       -> wrap_mmu_context()
- *          -> read_lock(&tasklist_lock)
- *
- * CPU#1:
- * sys_wait4() or release_task() or forget_original_parent()
- *    -> write_lock(&tasklist_lock)
- *    -> do_notify_parent()
- *       -> wake_up_parent()
- *          -> try_to_wake_up()
- *             -> spin_lock_irq(&parent_rq->lock)
- *
- * If the parent's rq happens to be on CPU#0, we'll wait for the rq->lock
- * of that CPU which will not be released, because there we wait for the
- * tasklist_lock to become available.
- */
 #define __ARCH_WANT_UNLOCKED_CTXSW
-
 #define ARCH_HAS_PREFETCH_SWITCH_STACK
 #define ia64_platform_is(x) (strcmp(x, platform_name) == 0)