Unverified Commit 3332f419 authored by Jisheng Zhang's avatar Jisheng Zhang Committed by Palmer Dabbelt
Browse files

riscv: mremap speedup - enable HAVE_MOVE_PUD and HAVE_MOVE_PMD 



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: default avatarJisheng Zhang <jszhang@kernel.org>
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent e88b3331

arch/riscv/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -82,6 +82,8 @@ 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

arch/riscv/include/asm/pgtable.h

+11 −0
Original line number Diff line number Diff line
@@ -241,6 +241,11 @@ static inline pte_t pmd_pte(pmd_t pmd) 
	return __pte(pmd_val(pmd));

}



static inline pte_t pud_pte(pud_t pud)

{

	return __pte(pud_val(pud));

}



/* Yields the page frame number (PFN) of a page table entry */

static inline unsigned long pte_pfn(pte_t pte)

{
@@ -570,6 +575,12 @@ static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, 
	return set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd));

}



static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,

				pud_t *pudp, pud_t pud)

{

	return set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud));

}



#ifdef CONFIG_TRANSPARENT_HUGEPAGE

static inline int pmd_trans_huge(pmd_t pmd)

{