Re: [PATCH] arm64/cpufeature: Convert hook_lock to raw_spin_lock_t in cpu_enable_ssbs()

[Catalin Marinas]

On Thu, May 30, 2019 at 12:30:58PM +0100, Julien Grall wrote:
> cpu_enable_ssbs() is called via stop_machine() as part of the cpu_enable
> callback. A spin lock is used to ensure the hook is registered before
> the rest of the callback is executed.
> 
> On -RT spin_lock() may sleep. However, all the callees in stop_machine()
> are expected to not sleep. Therefore a raw_spin_lock() is required here.
> 
> Given this is already done under stop_machine() and the work done under
> the lock is quite small, the latency should not increase too much.
> 
> Signed-off-by: Julien Grall <julien.grall@xxxxxxx>

Queued for 5.3. Thanks.

-- 
Catalin