Re: [PATCH] to fix xtime lock for in the RT kernel patch

From: Ingo Molnar
Date: Fri Jan 21 2005 - 01:37:44 EST



* George Anzinger <george@xxxxxxxxxx> wrote:

> It seems to me that we need to either do the attached or to rewrite
> the timer front end code to just gather the offset info and defer to
> the timer irq thread to update jiffies and the offset stuff. In
> either case we really can not split the two and we do need the
> xtime_lock protection.

how about the patch below? One of the important benefits of the threaded
timer IRQ is the ability to make xtime_lock a mutex.

Ingo

--- linux/arch/i386/kernel/time.c.orig2
+++ linux/arch/i386/kernel/time.c
@@ -313,6 +313,7 @@ irqreturn_t timer_interrupt(int irq, voi
write_seqlock(&xtime_lock);

cur_timer->mark_offset();
+ do_timer(regs);

do_timer_interrupt(irq, NULL, regs);

--- linux/include/asm-i386/mach-default/do_timer.h.orig2
+++ linux/include/asm-i386/mach-default/do_timer.h
@@ -16,7 +16,6 @@

static inline void do_timer_interrupt_hook(struct pt_regs *regs)
{
- do_timer(regs);
#ifndef CONFIG_SMP
update_process_times(user_mode(regs));
#endif
-
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