Commit c71799c1 authored by Heiko Carstens's avatar Heiko Carstens Committed by Avi Kivity
Browse files

KVM: s390: Improve pgste accesses 



There is no need to use interlocked updates when the rcp
lock is held. Therefore the simple bitops variants can be
used. This should improve performance.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarCarsten Otte <cotte@de.ibm.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent f603f073

include/asm-s390/pgtable.h

+6 −6
Original line number Diff line number Diff line
@@ -553,12 +553,12 @@ static inline void ptep_rcp_copy(pte_t *ptep) 


	skey = page_get_storage_key(page_to_phys(page));

	if (skey & _PAGE_CHANGED)

		set_bit(RCP_GC_BIT, pgste);

		set_bit_simple(RCP_GC_BIT, pgste);

	if (skey & _PAGE_REFERENCED)

		set_bit(RCP_GR_BIT, pgste);

	if (test_and_clear_bit(RCP_HC_BIT, pgste))

		set_bit_simple(RCP_GR_BIT, pgste);

	if (test_and_clear_bit_simple(RCP_HC_BIT, pgste))

		SetPageDirty(page);

	if (test_and_clear_bit(RCP_HR_BIT, pgste))

	if (test_and_clear_bit_simple(RCP_HR_BIT, pgste))

		SetPageReferenced(page);

#endif

}
@@ -732,8 +732,8 @@ static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, 
	young = ((page_get_storage_key(physpage) & _PAGE_REFERENCED) != 0);

	rcp_lock(ptep);

	if (young)

		set_bit(RCP_GR_BIT, pgste);

	young |= test_and_clear_bit(RCP_HR_BIT, pgste);

		set_bit_simple(RCP_GR_BIT, pgste);

	young |= test_and_clear_bit_simple(RCP_HR_BIT, pgste);

	rcp_unlock(ptep);

	return young;

#endif

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