MTRR: Fix race causing set_mtrr to go into infinite loop

Processors synchronization in set_mtrr requires the .gate field to be set
after .count field is properly initialized.  Without an explicit barrier,
the compiler was reordering those memory stores.  That was sometimes
causing a processor (in ipi_handler) to see the .gate change and decrement
.count before the latter is set by set_mtrr() (which then hangs in a
infinite loop with irqs disabled).

Signed-off-by: Loic Prylli <[email protected]>
Cc: Andi Kleen <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions