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Commit 68662f85 authored Jun 01, 2018 by Nicholas Piggin Committed by Michael Ellerman Jun 03, 2018

powerpc/64s/radix: prefetch user address in update_mmu_cache



Prefetch the faulting address in update_mmu_cache to give the page
table walker perhaps 100 cycles head start as locks are dropped and
the interrupt completed.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

parent f569bd94

arch/powerpc/mm/mem.c

+3 −1

Original line number	Original line	Diff line number	Diff line
	@@ -509,8 +509,10 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
	*/		*/
	unsigned long access, trap;		unsigned long access, trap;

	if (radix_enabled())		if (radix_enabled()) {
			prefetch((void *)address);
	return;		return;
			}

	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */		/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
	if (!pte_young(*ptep) \|\| address >= TASK_SIZE)		if (!pte_young(*ptep) \|\| address >= TASK_SIZE)

arch/powerpc/mm/pgtable-book3s64.c

+2 −1

Original line number	Original line	Diff line number	Diff line
	@@ -152,7 +152,8 @@ pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
	void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,		void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
	pmd_t *pmd)		pmd_t *pmd)
	{		{
	return;		if (radix_enabled())
			prefetch((void *)addr);
	}		}
	#endif /* CONFIG_TRANSPARENT_HUGEPAGE */		#endif /* CONFIG_TRANSPARENT_HUGEPAGE */