Re: [PATCH] ARM: support PREEMPT_DYNAMIC

[Russell King (Oracle)]

On Wed, Jul 31, 2024 at 06:03:11PM +0800, Jinjie Ruan wrote:
> On 2024/7/31 16:24, Russell King (Oracle) wrote:
> > On Wed, Jul 31, 2024 at 10:07:53AM +0800, Jinjie Ruan wrote:
> >>>  #ifdef CONFIG_PREEMPTION
> >>> +#ifdef CONFIG_PREEMPT_DYNAMIC
> >>> +	bl	need_irq_preemption
> >>> +	cmp	r0, #0
> >>> +	beq	2f
> >>> +#endif
> > 
> > Depending on the interrupt rate, this can be regarded as a fast path,
> > it would be nice if we could find a way to use static branches in
> > assembly code.
> It seems to be hard to use static keys in assembly code.
> 
> By the way, currently, most architectures have simplified assembly code
> and implemented its most functions in C functions. Does arm32 have this
> plan?

arm32 is effectively in maintenance mode; very little active development
is occuring. So, there are no plans to change the code without good
reason (as code changes without reason will needlessly affect its
stability.)

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