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linux/arch/sparc/include/asm/hugetlb.h
David S. Miller 0fbebed682 sparc64: Fix tsb_grow() in atomic context.
If our first THP installation for an MM is via the set_pmd_at() done
during khugepaged's collapsing we'll end up in tsb_grow() trying to do
a GFP_KERNEL allocation with several locks held.

Simply using GFP_ATOMIC in this situation is not the best option
because we really can't have this fail, so we'd really like to keep
this an order 0 GFP_KERNEL allocation if possible.

Also, doing the TSB allocation from khugepaged is a really bad idea
because we'll allocate it potentially from the wrong NUMA node in that
context.

So what we do is defer the hugepage TSB allocation until the first TLB
miss we take on a hugepage.  This is slightly tricky because we have
to handle two unusual cases:

1) Taking the first hugepage TLB miss in the window trap handler.
   We'll call the winfix_trampoline when that is detected.

2) An initial TSB allocation via TLB miss races with a hugetlb
   fault on another cpu running the same MM.  We handle this by
   unconditionally loading the TSB we see into the current cpu
   even if it's non-NULL at hugetlb_setup time.

Reported-by: Meelis Roos <mroos@ut.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-20 09:46:08 -08:00

98 lines
2.1 KiB
C

#ifndef _ASM_SPARC64_HUGETLB_H
#define _ASM_SPARC64_HUGETLB_H
#include <asm/page.h>
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte);
pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep);
static inline void hugetlb_prefault_arch_hook(struct mm_struct *mm)
{
}
static inline int is_hugepage_only_range(struct mm_struct *mm,
unsigned long addr,
unsigned long len) {
return 0;
}
/*
* If the arch doesn't supply something else, assume that hugepage
* size aligned regions are ok without further preparation.
*/
static inline int prepare_hugepage_range(struct file *file,
unsigned long addr, unsigned long len)
{
if (len & ~HPAGE_MASK)
return -EINVAL;
if (addr & ~HPAGE_MASK)
return -EINVAL;
return 0;
}
static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
unsigned long addr, unsigned long end,
unsigned long floor,
unsigned long ceiling)
{
free_pgd_range(tlb, addr, end, floor, ceiling);
}
static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep)
{
}
static inline int huge_pte_none(pte_t pte)
{
return pte_none(pte);
}
static inline pte_t huge_pte_wrprotect(pte_t pte)
{
return pte_wrprotect(pte);
}
static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
pte_t old_pte = *ptep;
set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
}
static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep,
pte_t pte, int dirty)
{
int changed = !pte_same(*ptep, pte);
if (changed) {
set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
flush_tlb_page(vma, addr);
}
return changed;
}
static inline pte_t huge_ptep_get(pte_t *ptep)
{
return *ptep;
}
static inline int arch_prepare_hugepage(struct page *page)
{
return 0;
}
static inline void arch_release_hugepage(struct page *page)
{
}
static inline void arch_clear_hugepage_flags(struct page *page)
{
}
#endif /* _ASM_SPARC64_HUGETLB_H */