Commit 9888a1ca authored by Zachary Amsden's avatar Zachary Amsden Committed by Linus Torvalds
Browse files

[PATCH] paravirt: pte clear not present 



Change pte_clear_full to a more appropriately named pte_clear_not_present,
allowing optimizations when not-present mapping changes need not be reflected
in the hardware TLB for protected page table modes.  There is also another
case that can use it in the fremap code.

Signed-off-by: default avatarZachary Amsden <zach@vmware.com>
Signed-off-by: default avatarJeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 3dc90795

include/asm-generic/pgtable.h

+7 −2
Original line number Diff line number Diff line
@@ -112,8 +112,13 @@ do { \ 
})

#endif



#ifndef __HAVE_ARCH_PTE_CLEAR_FULL

#define pte_clear_full(__mm, __address, __ptep, __full)			\

/*

 * Some architectures may be able to avoid expensive synchronization

 * primitives when modifications are made to PTE's which are already

 * not present, or in the process of an address space destruction.

 */

#ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL

#define pte_clear_not_present_full(__mm, __address, __ptep, __full)	\

do {									\

	pte_clear((__mm), (__address), (__ptep));			\

} while (0)

mm/fremap.c

+1 −1
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ static int zap_pte(struct mm_struct *mm, struct vm_area_struct *vma, 
	} else {

		if (!pte_file(pte))

			free_swap_and_cache(pte_to_swp_entry(pte));

		pte_clear(mm, addr, ptep);

		pte_clear_not_present_full(mm, addr, ptep, 0);

	}

	return !!page;

}

mm/memory.c

+1 −1
Original line number Diff line number Diff line
@@ -690,7 +690,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, 
			continue;

		if (!pte_file(ptent))

			free_swap_and_cache(pte_to_swp_entry(ptent));

		pte_clear_full(mm, addr, pte, tlb->fullmm);

		pte_clear_not_present_full(mm, addr, pte, tlb->fullmm);

	} while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0));



	add_mm_rss(mm, file_rss, anon_rss);

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