uml: fix timer switching

Fix up the switching between virtual and real timers.  The idle loop sleeps,
so the timer at that point must be real time.  At all other times, the timer
must be virtual.  Even when userspace is running, and the kernel is asleep,
the virtual timer is correct because the process timer will be running and the
process timer will be firing.

The timer switch used to be in the context switch and timer handler code.
This is moved to the idle loop and the signal handler, making it much more
clear why it is happening.

switch_timers now returns the old timer type so that it may be restored.  The
signal handler uses this in order to restore the previous timer type when it
returns.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index e861c8adb44f..12de1ea68370 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -250,7 +250,7 @@ extern void os_dump_core(void);
 /* time.c */
 #define BILLION (1000 * 1000 * 1000)
 
-extern void switch_timers(int to_real);
+extern int switch_timers(int to_real);
 extern void idle_sleep(int secs);
 extern int set_interval(int is_virtual);
 extern void disable_timer(void);