Andi Kleen <[EMAIL PROTECTED]> wrote: > > On Fri, Jan 14, 2005 at 10:28:41PM -0800, Andrew Morton wrote: > > Andi Kleen <[EMAIL PROTECTED]> wrote: > > > > > > This fixes a long standing race in 2.6 i386/x86-64 SMP boot. > > > The per CPU timers would only get initialized after an secondary > > > CPU was running. But during initialization the secondary CPU would > > > already enable interrupts to compute the jiffies. When a per > > > CPU timer fired in this window it would run into a BUG in timer.c > > > because the timer heap for that CPU wasn't fully initialized. > > > > Why don't we just not call calibrate_delay() on the secondaries? It > > doesn't seem to do anything. That way we can leave local interrupts > > disabled. > > It's used for the "accumulative bogomips". To quote Alan: > > /* > * Allow the user to impress friends. > */ > > But taking it away doesn't help because the timer startup on the BP > and the secondaries going into the idle loop isn't synchronized. > You could add a synchronization step, but it would be far more > complicated than fixing the ordering like I did.
I don't get it. By the time the secondaries enter the idle loop, they've already run init_timers_cpu() anyway. You patch doesn't address a secondary taking a timer interrupt prior to the BP having run init_timers(), does it? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
