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Commit 1dd38b6c authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Linus Torvalds
Browse files

mm: move vma_is_anonymous check within pmd_move_must_withdraw 

Independent of whether the vma is for anonymous memory, some arches like
ppc64 would like to override pmd_move_must_withdraw().

One option is to encapsulate the vma_is_anonymous() check for general
architectures inside pmd_move_must_withdraw() so that is always called
and architectures that need unconditional overriding can override this
function.  ppc64 needs to override the function when the MMU is
configured to use hash PTE's.

[bsingharora@gmail.com: reworked changelog]
Link: http://lkml.kernel.org/r/20161113150025.17942-1-aneesh.kumar@linux.vnet.ibm.com


Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 763b218d

arch/powerpc/include/asm/book3s/64/pgtable.h

+2 −1
Original line number Diff line number Diff line
@@ -1009,7 +1009,8 @@ static inline void pmdp_huge_split_prepare(struct vm_area_struct *vma, 
#define pmd_move_must_withdraw pmd_move_must_withdraw

struct spinlock;

static inline int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl,

					 struct spinlock *old_pmd_ptl)

					 struct spinlock *old_pmd_ptl,

					 struct vm_area_struct *vma)

{

	if (radix_enabled())

		return false;

include/asm-generic/pgtable.h

+0 −12
Original line number Diff line number Diff line
@@ -652,18 +652,6 @@ static inline pmd_t pmd_read_atomic(pmd_t *pmdp) 
}

#endif



#ifndef pmd_move_must_withdraw

static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl,

					 spinlock_t *old_pmd_ptl)

{

	/*

	 * With split pmd lock we also need to move preallocated

	 * PTE page table if new_pmd is on different PMD page table.

	 */

	return new_pmd_ptl != old_pmd_ptl;

}

#endif



/*

 * This function is meant to be used by sites walking pagetables with

 * the mmap_sem hold in read mode to protect against MADV_DONTNEED and

mm/huge_memory.c

+16 −2
Original line number Diff line number Diff line
@@ -1429,6 +1429,21 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, 
	return 1;

}



#ifndef pmd_move_must_withdraw

static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl,

					 spinlock_t *old_pmd_ptl,

					 struct vm_area_struct *vma)

{

	/*

	 * With split pmd lock we also need to move preallocated

	 * PTE page table if new_pmd is on different PMD page table.

	 *

	 * We also don't deposit and withdraw tables for file pages.

	 */

	return (new_pmd_ptl != old_pmd_ptl) && vma_is_anonymous(vma);

}

#endif



bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,

		  unsigned long new_addr, unsigned long old_end,

		  pmd_t *old_pmd, pmd_t *new_pmd, bool *need_flush)
@@ -1466,8 +1481,7 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, 
			force_flush = true;

		VM_BUG_ON(!pmd_none(*new_pmd));



		if (pmd_move_must_withdraw(new_ptl, old_ptl) &&

				vma_is_anonymous(vma)) {

		if (pmd_move_must_withdraw(new_ptl, old_ptl, vma)) {

			pgtable_t pgtable;

			pgtable = pgtable_trans_huge_withdraw(mm, old_pmd);

			pgtable_trans_huge_deposit(mm, new_pmd, pgtable);