Re: [PATCH V4 8/8] riscv: Add config of thread stack size

[Guo Ren]

On Tue, Sep 20, 2022 at 3:18 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Tue, Sep 20, 2022, at 2:46 AM, Guo Ren wrote:
>
> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> > index dfe600f3526c..8def456f328c 100644
> > --- a/arch/riscv/Kconfig
> > +++ b/arch/riscv/Kconfig
> > @@ -442,6 +442,16 @@ config IRQ_STACKS
> >           Add independent irq & softirq stacks for percpu to prevent
> > kernel stack
> >           overflows. We may save some memory footprint by disabling IRQ_STACKS.
> >
> > +config THREAD_SIZE
> > +       int "Kernel stack size (in bytes)" if EXPERT
> > +       range 4096 65536
> > +       default 8192 if 32BIT && !KASAN
> > +       default 32768 if 64BIT && KASAN
> > +       default 16384
> > +       help
> > +         Specify the Pages of thread stack size (from 4KB to 64KB), which also
> > +         affects irq stack size, which is equal to thread stack size.
>
> I still think this should be guarded in a way that prevents
> setting the stack to smaller than default values unless VMAP_STACK
> is set as well.
Current VMAP_STACK would double THREAD_SIZE. Let me see how to reduce
the VMAP_STACK.

>
>     Arnd



-- 
Best Regards
 Guo Ren