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

From: Ingo Molnar
Date: Fri Jan 21 2005 - 03:22:55 EST



* George Anzinger <george@xxxxxxxxxx> wrote:

> > how about the patch below? One of the important benefits of the
> > threaded timer IRQ is the ability to make xtime_lock a mutex.
>
> The problem is that that removes the
> cur_timer->mark_offset();
> do_timer(regs);
> in time. [...]

i'm not sure i understand what you mean. My change does:

| @@ -294,6 +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);

so ->mark_offset and do_timer() go together, and happen under
xtime_lock. What problem is there if we do this?

Ingo
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