[PATCH 3/9] ARM: smp: avoid using bitmasks and locks for IPIs, use hardware instead

[Catalin Marinas]

On Mon, 2010-11-15 at 17:58 +0000, Russell King - ARM Linux wrote:
> Avoid using bitmasks and locks in the percpu area for IPIs, and instead
> use individual software generated interrupts to identify the reason for
> the IPI.  This avoids the problems of having spinlocks in the percpu
> area.
> 
> Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
> ---
>  arch/arm/kernel/smp.c |   87 ++++++++++++++----------------------------------
>  1 files changed, 26 insertions(+), 61 deletions(-)
> 
> diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
> index 7a236db..78d55c6 100644
> --- a/arch/arm/kernel/smp.c
> +++ b/arch/arm/kernel/smp.c
[...]
>  enum ipi_msg_type {
> -       IPI_TIMER,
> +       IPI_TIMER = 2,
>         IPI_RESCHEDULE,
>         IPI_CALL_FUNC,
>         IPI_CALL_FUNC_SINGLE,

Maybe a comment here on why this starts at 2. People may wonder in the
future.

-- 
Catalin