On Sun, Dec 31, 2023 at 07:37:33AM +0100, Alexandre Ghiti wrote:
> On 19/12/2023 18:50, Jisheng Zhang wrote:
> > Activate the fast gup for riscv mmu platforms. Here are some
> > GUP_FAST_BENCHMARK performance numbers:
> >
> > Before the patch:
> > GUP_FAST_BENCHMARK: Time: get:53203 put:5085 us
> >
> > After the patch:
> > GUP_FAST_BENCHMARK: Time: get:17711 put:5060 us
>
>
> On which platform did you run this benchmark?
T-HEAD th1520(cpufreq isn't enabled since the clk/pll isn't upstreamed,
so cpu is running at the default freq set by u-boot)
>
>
> >
> > The get time is reduced by 66.7%! IOW, 3x get speed!
>
>
> Well done!
>
> Thanks,
>
> Alex
>
>
> >
> > Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
> > ---
> > arch/riscv/Kconfig | 1 +
> > arch/riscv/include/asm/pgtable.h | 6 ++++++
> > 2 files changed, 7 insertions(+)
> >
> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> > index d3555173d9f4..04df9920282d 100644
> > --- a/arch/riscv/Kconfig
> > +++ b/arch/riscv/Kconfig
> > @@ -119,6 +119,7 @@ config RISCV
> > select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
> > select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
> > select HAVE_EBPF_JIT if MMU
> > + select HAVE_FAST_GUP if MMU
> > select HAVE_FUNCTION_ARG_ACCESS_API
> > select HAVE_FUNCTION_ERROR_INJECTION
> > select HAVE_GCC_PLUGINS
> > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> > index ab00235b018f..c6eb214139e6 100644
> > --- a/arch/riscv/include/asm/pgtable.h
> > +++ b/arch/riscv/include/asm/pgtable.h
> > @@ -673,6 +673,12 @@ static inline int pmd_write(pmd_t pmd)
> > return pte_write(pmd_pte(pmd));
> > }
> > +#define pud_write pud_write
> > +static inline int pud_write(pud_t pud)
> > +{
> > + return pte_write(pud_pte(pud));
> > +}
> > +
> > static inline int pmd_dirty(pmd_t pmd)
> > {
> > return pte_dirty(pmd_pte(pmd));
