Re: [PATCH -next v7 5/7] arm64: entry: Refactor preempt_schedule_irq() check code

[Ada Couprie Diaz <ada.coupriediaz@xxxxxxx>]

On 06/08/2025 07:39, Jinjie Ruan wrote:

> On 2025/8/5 23:06, Ada Couprie Diaz wrote:
> > Hi Jinjie,
> >
> > On 29/07/2025 02:54, Jinjie Ruan wrote:
> > > ARM64 requires an additional check whether to reschedule on return
> > > from interrupt. So add arch_irqentry_exit_need_resched() as the default
> > > NOP implementation and hook it up into the need_resched() condition in
> > > raw_irqentry_exit_cond_resched(). This allows ARM64 to implement
> > > the architecture specific version for switching over to
> > > the generic entry code.
> > > [...]
> > I've had some trouble reviewing this patch : on the one hand because
> > I didn't notice `arch_irqentry_exit_need_resched()` was added in
> > the common entry code, which is on me !
> > On the other hand, I felt that the patch itself was a bit disconnected :
> > we add `arch_irqentry_exit_need_resched()` in the common entry code,
> > with a default NOP, but in the same function we add to arm64,
> > while mentioning that this is for arm64's additional checks,
> > which we only implement in patch 7.
> Yes, it does.
>
> > Would it make sense to move the `arch_irqentry_exit_need_resched()`
> > part of the patch to patch 7, so that the introduction and
> > arch-specific implementation appear together ?
> > To me it seems easier to wrap my head around, as it would look like
> > "Move arm64 to generic entry, but it does additional checks : add a new
> > arch-specific function controlling re-scheduling, defaulting to true,
> > and implement it for arm64". I feel it could help making patch 7's
> > commit message clearer as well.
> >
> >  From what I gathered on the archive `arch_irqentry_exit_need_resched()`
> > being added here was suggested previously, so others might not have the
> > same opinion.
> Yes, introduce `arch_irqentry_exit_need_resched()` here may help
> understand the patch's refactoring purpose.
I can see that as well.
I shared my opinion in case it could be useful, but as I mentioned
in my reply to the cover : it's not a big issue and I'm happy for
`arch_irqentry_exit_need_resched()` to be implemented here if that
makes more sense !
> > Maybe improving the commit message and comment for this would be enough
> > as well, as per my suggestions above.
> Thank you! I'll improve the commit message and comment.
My pleasure !
Ada