From b160fb6309dc907cbd8849e549d83badb86dd35b Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Tue, 16 Oct 2007 01:27:26 -0700 Subject: uml: eliminate interrupts in the idle loop Now, the idle loop now longer needs SIGALRM firing - it can just sleep for the requisite amount of time and fake a timer interrupt when it finishes. Any use of ITIMER_REAL now goes away. disable_timer only turns off ITIMER_VIRTUAL. switch_timers is no longer needed, so it, and all calls, goes away. disable_timer now returns the amount of time remaining on the timer. default_idle uses this to tell idle_sleep how long to sleep. idle_sleep will call alarm_handler if nanosleep returns 0, which is the case if it didn't return early due to an interrupt. Otherwise, it just returns. Signed-off-by: Jeff Dike Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/kernel/process.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'arch/um/kernel') diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index aef494b6b81a..0eae00b3e588 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -235,6 +235,8 @@ void initial_thread_cb(void (*proc)(void *), void *arg) void default_idle(void) { + unsigned long long nsecs; + while(1) { /* endless idle loop with no priority at all */ @@ -246,9 +248,8 @@ void default_idle(void) schedule(); tick_nohz_stop_sched_tick(); - switch_timers(1); - idle_sleep(10); - switch_timers(0); + nsecs = disable_timer(); + idle_sleep(nsecs); tick_nohz_restart_sched_tick(); } } -- cgit 1.4.1