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

Guo Ren
2022-09-21T06:13:52Z

On Tue, Sep 20, 2022 at 3:18 PM Arnd Bergmann <arnd@arndb.de> 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