Messages in this thread |  | | Date | Sat, 22 May 2021 08:58:50 -0700 (PDT) | Subject | Re: [RFT PATCH] riscv: mremap speedup - enable HAVE_MOVE_PUD and HAVE_MOVE_PMD | From | Palmer Dabbelt <> |
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On Fri, 16 Apr 2021 09:37:22 PDT (-0700), jszhang3@mail.ustc.edu.cn wrote: > From: Jisheng Zhang <jszhang@kernel.org> > > HAVE_MOVE_PUD enables remapping pages at the PUD level if both the source > and destination addresses are PUD-aligned. > HAVE_MOVE_PMD does similar speedup on the PMD level. > > With HAVE_MOVE_PUD enabled, there is about a 143x improvement on qemu > With HAVE_MOVE_PMD enabled, there is about a 5x improvement on qemu > > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > --- > Hi all, > > After reading the risc-v privileged spec, I think it's safe to support > the HAVE_MOVE_PUD and HAVE_MOVE_PMD optimization on riscv. The patch passed > the mremap_test on QEMU. However this can't be tested on real HW due to lack > of HW boards, this is the reason why I mark this patch as RFT. I hope I can > buy a sipeed Allwiner D1 SoC powered SBC soon, at least I can test > HAVE_MOVE_PMD. Helping me to test on real HW is appreciated! > > Thanks > > arch/riscv/Kconfig | 2 ++ > arch/riscv/include/asm/pgtable.h | 12 ++++++++++++ > 2 files changed, 14 insertions(+) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index e8074d248457..37660de68b00 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -80,6 +80,8 @@ config RISCV > select HAVE_KPROBES > select HAVE_KPROBES_ON_FTRACE > select HAVE_KRETPROBES > + select HAVE_MOVE_PMD > + select HAVE_MOVE_PUD > select HAVE_PCI > select HAVE_PERF_EVENTS > select HAVE_PERF_REGS > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index ebf817c1bdf4..287733b95d10 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -360,6 +360,18 @@ static inline void set_pte_at(struct mm_struct *mm, > set_pte(ptep, pteval); > } > > +static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, > + pmd_t *pmdp, pmd_t pmd) > +{ > + set_pmd(pmdp, pmd); > +} > + > +static inline void set_pud_at(struct mm_struct *mm, unsigned long addr, > + pud_t *pudp, pud_t pud) > +{ > + set_pud(pudp, pud); > +} > + > static inline void pte_clear(struct mm_struct *mm, > unsigned long addr, pte_t *ptep) > {
Thanks, this is on for-next.
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