Re: [PATCH] Documentation: preempt-locking: Use better example

From: Jonathan Corbet
Date: Fri Oct 12 2018 - 13:37:00 EST


On Mon, 8 Oct 2018 14:15:15 +0100
Andrew Murray <andrew.murray@xxxxxxx> wrote:

> The existing wording implies that the use of spin_unlock whilst irqs are
> disabled might trigger a reschedule. However the preemptible() test in
> preempt_schedule will prevent a reschedule if irqs are disabled.
>
> Lets improve the clarity of this wording to change the example from
> spin_unlock to cond_resched() and cond_resched_lock() as these are
> functions that will trigger a reschedule if the preempt count is 0 without
> testing that irqs are disabled.
>
> Also remove the 'Last Updated' line as this is not up to date and better
> tracked via GIT.
>
> Signed-off-by: Andrew Murray <andrew.murray@xxxxxxx>

I've applied this, but that document is ... old. It sure would be nice if
somebody found the energy to write a proper locking document for current
kernels...:)

Thanks,

jon