On Wed, 2003-01-29 at 02:26, Andrew Morton wrote:

"David S. Miller" [off-list ref] wrote:

quoted

   From: Russell King [off-list ref]
   Date: Wed, 29 Jan 2003 09:59:49 +0000
   
   	/* This function must be called with interrupts disabled
   
   which hasn't been true for some time, and is even less true now that
   local IRQs don't get disabled.  Does this matter... for UP?

I disable local IRQs during gettimeofday() on sparc.

These locks definitely need to be taken with IRQs disabled.
Why isn't x86 doing that?

Darned if I know.  Looks like Andrea's kernel will deadlock if
arch/i386/kernel/time.c:timer_interrupt() takes i8253_lock
while that cpu is holding the same lock in do_slow_gettimeoffset().

Rather than disabling interrupts in the i386 do_gettimeofday
why not just change spin_lock(&i8253_lock) to spin_lock_irqsave
in timer_pit.c

-- 
Stephen Hemminger [off-list ref]
Open Source Devlopment Lab


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