| Message ID | 1368778503-23230-2-git-send-email-aneesh.kumar@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> writes: > From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> > > We find all the overlapping vma and mark them such that we don't allocate > hugepage in that range. Also we split existing huge page so that the > normal page hash can be invalidated and new page faulted in with new > protection bits. > > Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> > --- > arch/powerpc/mm/subpage-prot.c | 27 +++++++++++++++++++++++++++ > 1 file changed, 27 insertions(+) > > diff --git a/arch/powerpc/mm/subpage-prot.c b/arch/powerpc/mm/subpage-prot.c > index 7c415dd..33fd329 100644 > --- a/arch/powerpc/mm/subpage-prot.c > +++ b/arch/powerpc/mm/subpage-prot.c > @@ -130,6 +130,14 @@ static void subpage_prot_clear(unsigned long addr, unsigned long len) > up_write(&mm->mmap_sem); > } > > +static int subpage_walk_pmd_entry(pmd_t *pmd, unsigned long addr, > + unsigned long end, struct mm_walk *walk) > +{ > + struct vm_area_struct *vma = walk->private; > + split_huge_page_pmd(vma, addr, pmd); > + return 0; > +} > + > /* > * Copy in a subpage protection map for an address range. > * The map has 2 bits per 4k subpage, so 32 bits per 64k page. > @@ -149,6 +157,12 @@ long sys_subpage_prot(unsigned long addr, unsigned long len, u32 __user *map) > size_t nw; > unsigned long next, limit; > int err; > + struct vm_area_struct *vma; > + > + struct mm_walk subpage_proto_walk = { > + .mm = mm, > + .pmd_entry = subpage_walk_pmd_entry, > + }; > > /* Check parameters */ > if ((addr & ~PAGE_MASK) || (len & ~PAGE_MASK) || > @@ -168,6 +182,19 @@ long sys_subpage_prot(unsigned long addr, unsigned long len, u32 __user *map) > return -EFAULT; > > down_write(&mm->mmap_sem); > + > + /* > + * We don't try too hard, we just mark all the vma in that range > + * VM_NOHUGEPAGE and split them. > + */ > + for (vma = find_vma(mm, addr); > + (vma && vma->vm_end < (addr + len)); vma = vma->vm_next) { should be, Missed commit -amend (vma && vma->vm_start < (addr + len)); vma = vma->vm_next) { > + vma->vm_flags |= VM_NOHUGEPAGE; > + subpage_proto_walk.private = vma; > + walk_page_range(vma->vm_start, vma->vm_end, > + &subpage_proto_walk); > + } > for (limit = addr + len; addr < limit; addr = next) { > next = pmd_addr_end(addr, limit); > err = -ENOMEM; -aneesh
diff --git a/arch/powerpc/mm/subpage-prot.c b/arch/powerpc/mm/subpage-prot.c index 7c415dd..33fd329 100644 --- a/arch/powerpc/mm/subpage-prot.c +++ b/arch/powerpc/mm/subpage-prot.c @@ -130,6 +130,14 @@ static void subpage_prot_clear(unsigned long addr, unsigned long len) up_write(&mm->mmap_sem); } +static int subpage_walk_pmd_entry(pmd_t *pmd, unsigned long addr, + unsigned long end, struct mm_walk *walk) +{ + struct vm_area_struct *vma = walk->private; + split_huge_page_pmd(vma, addr, pmd); + return 0; +} + /* * Copy in a subpage protection map for an address range. * The map has 2 bits per 4k subpage, so 32 bits per 64k page. @@ -149,6 +157,12 @@ long sys_subpage_prot(unsigned long addr, unsigned long len, u32 __user *map) size_t nw; unsigned long next, limit; int err; + struct vm_area_struct *vma; + + struct mm_walk subpage_proto_walk = { + .mm = mm, + .pmd_entry = subpage_walk_pmd_entry, + }; /* Check parameters */ if ((addr & ~PAGE_MASK) || (len & ~PAGE_MASK) || @@ -168,6 +182,19 @@ long sys_subpage_prot(unsigned long addr, unsigned long len, u32 __user *map) return -EFAULT; down_write(&mm->mmap_sem); + + /* + * We don't try too hard, we just mark all the vma in that range + * VM_NOHUGEPAGE and split them. + */ + for (vma = find_vma(mm, addr); + (vma && vma->vm_end < (addr + len)); vma = vma->vm_next) { + + vma->vm_flags |= VM_NOHUGEPAGE; + subpage_proto_walk.private = vma; + walk_page_range(vma->vm_start, vma->vm_end, + &subpage_proto_walk); + } for (limit = addr + len; addr < limit; addr = next) { next = pmd_addr_end(addr, limit); err = -ENOMEM;