mm: add p[te|md] protnone helpers for use by NUMA balancing

This is a preparatory patch that introduces protnone helpers for automatic
NUMA balancing.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mel Gorman 2015-02-12 14:58:19 -08:00 committed by Linus Torvalds
parent 5d83306213
commit e7bb4b6d16
3 changed files with 52 additions and 0 deletions

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@ -40,6 +40,22 @@ static inline int pte_none(pte_t pte) { return (pte_val(pte) & ~_PTE_NONE_MASK)
static inline pgprot_t pte_pgprot(pte_t pte) { return __pgprot(pte_val(pte) & PAGE_PROT_BITS); }
#ifdef CONFIG_NUMA_BALANCING
/*
* These work without NUMA balancing but the kernel does not care. See the
* comment in include/asm-generic/pgtable.h . On powerpc, this will only
* work for user pages and always return true for kernel pages.
*/
static inline int pte_protnone(pte_t pte)
{
return (pte_val(pte) &
(_PAGE_PRESENT | _PAGE_USER)) == _PAGE_PRESENT;
}
static inline int pmd_protnone(pmd_t pmd)
{
return pte_protnone(pmd_pte(pmd));
}
static inline int pte_present(pte_t pte)
{
return pte_val(pte) & _PAGE_NUMA_MASK;

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@ -483,6 +483,22 @@ static inline int pmd_present(pmd_t pmd)
_PAGE_NUMA);
}
#ifdef CONFIG_NUMA_BALANCING
/*
* These work without NUMA balancing but the kernel does not care. See the
* comment in include/asm-generic/pgtable.h
*/
static inline int pte_protnone(pte_t pte)
{
return pte_flags(pte) & _PAGE_PROTNONE;
}
static inline int pmd_protnone(pmd_t pmd)
{
return pmd_flags(pmd) & _PAGE_PROTNONE;
}
#endif /* CONFIG_NUMA_BALANCING */
static inline int pmd_none(pmd_t pmd)
{
/* Only check low word on 32-bit platforms, since it might be

View File

@ -673,6 +673,26 @@ static inline int pmd_trans_unstable(pmd_t *pmd)
#endif
}
#ifndef CONFIG_NUMA_BALANCING
/*
* Technically a PTE can be PROTNONE even when not doing NUMA balancing but
* the only case the kernel cares is for NUMA balancing and is only ever set
* when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked
* _PAGE_PROTNONE so by by default, implement the helper as "always no". It
* is the responsibility of the caller to distinguish between PROT_NONE
* protections and NUMA hinting fault protections.
*/
static inline int pte_protnone(pte_t pte)
{
return 0;
}
static inline int pmd_protnone(pmd_t pmd)
{
return 0;
}
#endif /* CONFIG_NUMA_BALANCING */
#ifdef CONFIG_NUMA_BALANCING
/*
* _PAGE_NUMA distinguishes between an unmapped page table entry, an entry that