From: Jisheng Zhang <[email protected]>
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 <[email protected]>
---
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)
{
--
2.31.0
On Fri, 16 Apr 2021 09:37:22 PDT (-0700), [email protected] wrote:
> From: Jisheng Zhang <[email protected]>
>
> 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 <[email protected]>
> ---
> 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.