Re: [PATCH] tee: optee: remove need_resched() before cond_resched()

[Rouven Czerwinski]

Hi Jens,

On 29.01.21 14:29, Jens Wiklander wrote:
> Hi Rouven and Sumit,
>
> On Mon, Jan 25, 2021 at 10:58 AM Jens Wiklander via OP-TEE
> <op-tee@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > Hi Rouven and Sumit,
> >
> > On Mon, Jan 25, 2021 at 10:55 AM Jens Wiklander
> > <jens.wiklander@xxxxxxxxxx> wrote:
> > > Testing need_resched() before cond_resched() is not needed as an
> > > equivalent test is done internally in cond_resched(). So drop the
> > > need_resched() test.
> > >
> > > Fixes: dcb3b06d9c34 ("tee: optee: replace might_sleep with cond_resched")
> > > Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
> > > ---
> > >   drivers/tee/optee/call.c | 3 +--
> > >   1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > Can you please test to see that this works in your setups too?
>
> Does this work for you? I'd like to get this patch ready for v5.12.

Yes it does. I also looked at it right after Arnds mail, so for future 
reference:


cond_resched()

  _cond_resched() (ifndef CONFIG_PREEMPTION)

    should_resched(0)

      tif_need_resched() (+ preempt_count == 0 for current thread)



while:



need_resched()

  tif_need_resched()


You can add my
Reviewed-by: Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx>

I also retested on the STM32-DK2 and the problem remains fixed:

Tested-by: Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx>

Regrads and thanks for the patch,
Rouven