Skip to content

Commit

Permalink
mm: remove unused savedwrite infrastructure
Browse files Browse the repository at this point in the history 
NUMA hinting no longer uses savedwrite, let's rip it out.

... and while at it, drop __pte_write() and __pmd_write() on ppc64.

Link: https://lkml.kernel.org/r/20221108174652.198904-7-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  • Loading branch information
David Hildenbrand authored and Andrew Morton committed Nov 30, 2022
1 parent 6a56ccb commit d637915
Show file tree
Hide file tree
Showing 4 changed files with 5 additions and 133 deletions.
80 changes: 4 additions & 76 deletions arch/powerpc/include/asm/book3s/64/pgtable.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -401,35 +401,9 @@ static inline int __ptep_test_and_clear_young(struct mm_struct *mm,
#define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
#define pmdp_clear_flush_young pmdp_test_and_clear_young

static inline int __pte_write(pte_t pte)
{
return !!(pte_raw(pte) & cpu_to_be64(_PAGE_WRITE));
}

#ifdef CONFIG_NUMA_BALANCING
#define pte_savedwrite pte_savedwrite
static inline bool pte_savedwrite(pte_t pte)
{
/*
* Saved write ptes are prot none ptes that doesn't have
* privileged bit sit. We mark prot none as one which has
* present and pviliged bit set and RWX cleared. To mark
* protnone which used to have _PAGE_WRITE set we clear
* the privileged bit.
*/
return !(pte_raw(pte) & cpu_to_be64(_PAGE_RWX | _PAGE_PRIVILEGED));
}
#else
#define pte_savedwrite pte_savedwrite
static inline bool pte_savedwrite(pte_t pte)
{
return false;
}
#endif

static inline int pte_write(pte_t pte)
{
return __pte_write(pte) || pte_savedwrite(pte);
return !!(pte_raw(pte) & cpu_to_be64(_PAGE_WRITE));
}

static inline int pte_read(pte_t pte)
Expand All @@ -441,24 +415,16 @@ static inline int pte_read(pte_t pte)
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
if (__pte_write(*ptep))
if (pte_write(*ptep))
pte_update(mm, addr, ptep, _PAGE_WRITE, 0, 0);
else if (unlikely(pte_savedwrite(*ptep)))
pte_update(mm, addr, ptep, 0, _PAGE_PRIVILEGED, 0);
}

#define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
/*
* We should not find protnone for hugetlb, but this complete the
* interface.
*/
if (__pte_write(*ptep))
if (pte_write(*ptep))
pte_update(mm, addr, ptep, _PAGE_WRITE, 0, 1);
else if (unlikely(pte_savedwrite(*ptep)))
pte_update(mm, addr, ptep, 0, _PAGE_PRIVILEGED, 1);
}

#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
Expand Down Expand Up @@ -535,36 +501,6 @@ static inline int pte_protnone(pte_t pte)
return (pte_raw(pte) & cpu_to_be64(_PAGE_PRESENT | _PAGE_PTE | _PAGE_RWX)) ==
cpu_to_be64(_PAGE_PRESENT | _PAGE_PTE);
}

#define pte_mk_savedwrite pte_mk_savedwrite
static inline pte_t pte_mk_savedwrite(pte_t pte)
{
/*
* Used by Autonuma subsystem to preserve the write bit
* while marking the pte PROT_NONE. Only allow this
* on PROT_NONE pte
*/
VM_BUG_ON((pte_raw(pte) & cpu_to_be64(_PAGE_PRESENT | _PAGE_RWX | _PAGE_PRIVILEGED)) !=
cpu_to_be64(_PAGE_PRESENT | _PAGE_PRIVILEGED));
return __pte_raw(pte_raw(pte) & cpu_to_be64(~_PAGE_PRIVILEGED));
}

#define pte_clear_savedwrite pte_clear_savedwrite
static inline pte_t pte_clear_savedwrite(pte_t pte)
{
/*
* Used by KSM subsystem to make a protnone pte readonly.
*/
VM_BUG_ON(!pte_protnone(pte));
return __pte_raw(pte_raw(pte) | cpu_to_be64(_PAGE_PRIVILEGED));
}
#else
#define pte_clear_savedwrite pte_clear_savedwrite
static inline pte_t pte_clear_savedwrite(pte_t pte)
{
VM_WARN_ON(1);
return __pte_raw(pte_raw(pte) & cpu_to_be64(~_PAGE_WRITE));
}
#endif /* CONFIG_NUMA_BALANCING */

static inline bool pte_hw_valid(pte_t pte)
Expand Down Expand Up @@ -641,8 +577,6 @@ static inline unsigned long pte_pfn(pte_t pte)
/* Generic modifiers for PTE bits */
static inline pte_t pte_wrprotect(pte_t pte)
{
if (unlikely(pte_savedwrite(pte)))
return pte_clear_savedwrite(pte);
return __pte_raw(pte_raw(pte) & cpu_to_be64(~_PAGE_WRITE));
}

Expand Down Expand Up @@ -1139,8 +1073,6 @@ static inline pte_t *pmdp_ptep(pmd_t *pmd)
#define pmd_mkclean(pmd) pte_pmd(pte_mkclean(pmd_pte(pmd)))
#define pmd_mkyoung(pmd) pte_pmd(pte_mkyoung(pmd_pte(pmd)))
#define pmd_mkwrite(pmd) pte_pmd(pte_mkwrite(pmd_pte(pmd)))
#define pmd_mk_savedwrite(pmd) pte_pmd(pte_mk_savedwrite(pmd_pte(pmd)))
#define pmd_clear_savedwrite(pmd) pte_pmd(pte_clear_savedwrite(pmd_pte(pmd)))

#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
#define pmd_soft_dirty(pmd) pte_soft_dirty(pmd_pte(pmd))
Expand All @@ -1162,8 +1094,6 @@ static inline int pmd_protnone(pmd_t pmd)
#endif /* CONFIG_NUMA_BALANCING */

#define pmd_write(pmd) pte_write(pmd_pte(pmd))
#define __pmd_write(pmd) __pte_write(pmd_pte(pmd))
#define pmd_savedwrite(pmd) pte_savedwrite(pmd_pte(pmd))

#define pmd_access_permitted pmd_access_permitted
static inline bool pmd_access_permitted(pmd_t pmd, bool write)
Expand Down Expand Up @@ -1241,10 +1171,8 @@ static inline int __pmdp_test_and_clear_young(struct mm_struct *mm,
static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp)
{
if (__pmd_write((*pmdp)))
if (pmd_write(*pmdp))
pmd_hugepage_update(mm, addr, pmdp, _PAGE_WRITE, 0);
else if (unlikely(pmd_savedwrite(*pmdp)))
pmd_hugepage_update(mm, addr, pmdp, 0, _PAGE_PRIVILEGED);
}

/*
Expand Down
2 changes: 1 addition & 1 deletion arch/powerpc/kvm/book3s_hv_rm_mmu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -265,7 +265,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
}
pte = kvmppc_read_update_linux_pte(ptep, writing);
if (pte_present(pte) && !pte_protnone(pte)) {
if (writing && !__pte_write(pte))
if (writing && !pte_write(pte))
/* make the actual HPTE be read-only */
ptel = hpte_make_readonly(ptel);
is_ci = pte_ci(pte);
Expand Down
24 changes: 0 additions & 24 deletions include/linux/pgtable.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -503,30 +503,6 @@ static inline pte_t pte_sw_mkyoung(pte_t pte)
#define pte_sw_mkyoung pte_sw_mkyoung
#endif

#ifndef pte_savedwrite
#define pte_savedwrite pte_write
#endif

#ifndef pte_mk_savedwrite
#define pte_mk_savedwrite pte_mkwrite
#endif

#ifndef pte_clear_savedwrite
#define pte_clear_savedwrite pte_wrprotect
#endif

#ifndef pmd_savedwrite
#define pmd_savedwrite pmd_write
#endif

#ifndef pmd_mk_savedwrite
#define pmd_mk_savedwrite pmd_mkwrite
#endif

#ifndef pmd_clear_savedwrite
#define pmd_clear_savedwrite pmd_wrprotect
#endif

#ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline void pmdp_set_wrprotect(struct mm_struct *mm,
Expand Down
32 changes: 0 additions & 32 deletions mm/debug_vm_pgtable.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -171,18 +171,6 @@ static void __init pte_advanced_tests(struct pgtable_debug_args *args)
ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1);
}

static void __init pte_savedwrite_tests(struct pgtable_debug_args *args)
{
pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot_none);

if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
return;

pr_debug("Validating PTE saved write\n");
WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
WARN_ON(pte_savedwrite(pte_clear_savedwrite(pte_mk_savedwrite(pte))));
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)
{
Expand Down Expand Up @@ -302,22 +290,6 @@ static void __init pmd_leaf_tests(struct pgtable_debug_args *args)
WARN_ON(!pmd_leaf(pmd));
}

static void __init pmd_savedwrite_tests(struct pgtable_debug_args *args)
{
pmd_t pmd;

if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
return;

if (!has_transparent_hugepage())
return;

pr_debug("Validating PMD saved write\n");
pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot_none);
WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));
WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));
}

#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx)
{
Expand Down Expand Up @@ -451,7 +423,6 @@ static void __init pmd_advanced_tests(struct pgtable_debug_args *args) { }
static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }
static void __init pmd_leaf_tests(struct pgtable_debug_args *args) { }
static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }
static void __init pmd_savedwrite_tests(struct pgtable_debug_args *args) { }
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
Expand Down Expand Up @@ -1288,9 +1259,6 @@ static int __init debug_vm_pgtable(void)
pmd_leaf_tests(&args);
pud_leaf_tests(&args);

pte_savedwrite_tests(&args);
pmd_savedwrite_tests(&args);

pte_special_tests(&args);
pte_protnone_tests(&args);
pmd_protnone_tests(&args);
Expand Down

0 comments on commit d637915

Please sign in to comment.