[PATCH] sched: cleanup context switch locking
Instead of requiring architecture code to interact with the scheduler's
locking implementation, provide a couple of defines that can be used by the
architecture to request runqueue unlocked context switches, and ask for
interrupts to be enabled over the context switch.
Also replaces the "switch_lock" used by these architectures with an oncpu
flag (note, not a potentially slow bitflag). This eliminates one bus
locked memory operation when context switching, and simplifies the
task_running function.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-ia64/system.h b/include/asm-ia64/system.h
index 6f516e7..cd2cf76 100644
--- a/include/asm-ia64/system.h
+++ b/include/asm-ia64/system.h
@@ -183,8 +183,6 @@
#ifdef __KERNEL__
-#define prepare_to_switch() do { } while(0)
-
#ifdef CONFIG_IA32_SUPPORT
# define IS_IA32_PROCESS(regs) (ia64_psr(regs)->is != 0)
#else
@@ -274,13 +272,7 @@
* of that CPU which will not be released, because there we wait for the
* tasklist_lock to become available.
*/
-#define prepare_arch_switch(rq, next) \
-do { \
- spin_lock(&(next)->switch_lock); \
- spin_unlock(&(rq)->lock); \
-} while (0)
-#define finish_arch_switch(rq, prev) spin_unlock_irq(&(prev)->switch_lock)
-#define task_running(rq, p) ((rq)->curr == (p) || spin_is_locked(&(p)->switch_lock))
+#define __ARCH_WANT_UNLOCKED_CTXSW
#define ia64_platform_is(x) (strcmp(x, platform_name) == 0)