At 10:40 AM -0400 2001-10-06, Thomas Hood wrote:
>On Sat, 2001-10-06 at 09:13, Alan Cox wrote:
>> > No, but what if the rtc interrupts while the lock is held in this
>> > bit of code?
>>
>> Thats fine. It wont take the lock
>
>But the first line of irq_interrupt() is:
> spin_lock (&rtc_lock);
>
>If one has a multi-processor machine, and CPUx is going through
>the bootflag code, which takes the rtc_lock, and that CPU is
>interrupted and enters rtc_interrupt(), which tries to take the
>rtc_lock, won't it deadlock?
>
>If not, then I'm missing some clue about how these spinlocks work.
rtc_interrupt(), you mean.
Even if there weren't current interrupt code doing CMOS accesses, it
would seem prudent to assume that there might be eventually, the
RTC/NVRAM being a multi-purpose shared resource.
-- /Jonathan Lundell. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sun Oct 07 2001 - 21:00:41 EST