diff options
| author | Konstantin Khlebnikov <khlebnikov@openvz.org> | 2012-10-08 16:28:40 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-09 16:22:17 +0900 |
| commit | 4b6e1e37026ec7dae9b23d78ffcebdd5ddb1bfa1 (patch) | |
| tree | 10200483a705005f41f543ed433581409cf2bf5f /mm/memory.c | |
| parent | cc2383ec06be093789469852e1fe96e1148e9a2c (diff) | |
| download | lwn-4b6e1e37026ec7dae9b23d78ffcebdd5ddb1bfa1.tar.gz lwn-4b6e1e37026ec7dae9b23d78ffcebdd5ddb1bfa1.zip | |
mm: kill vma flag VM_INSERTPAGE
Merge VM_INSERTPAGE into VM_MIXEDMAP. VM_MIXEDMAP VMA can mix pure-pfn
ptes, special ptes and normal ptes.
Now copy_page_range() always copies VM_MIXEDMAP VMA on fork like
VM_PFNMAP. If driver populates whole VMA at mmap() it probably not
expects page-faults.
This patch removes special check from vma_wants_writenotify() which
disables pages write tracking for VMA populated via vm_instert_page().
BDI below mapped file should not use dirty-accounting, moreover
do_wp_page() can handle this.
vm_insert_page() still marks vma after first usage. Usually it is called
from f_op->mmap() handler under mm->mmap_sem write-lock, so it able to
change vma->vm_flags. Caller must set VM_MIXEDMAP at mmap time if it
wants to call this function from other places, for example from page-fault
handler.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Venkatesh Pallipadi <venki@google.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c index 655e1429388a..7b1e4feaec06 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1047,7 +1047,8 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, * readonly mappings. The tradeoff is that copy_page_range is more * efficient than faulting. */ - if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_PFNMAP|VM_INSERTPAGE))) { + if (!(vma->vm_flags & (VM_HUGETLB | VM_NONLINEAR | + VM_PFNMAP | VM_MIXEDMAP))) { if (!vma->anon_vma) return 0; } @@ -2085,6 +2086,11 @@ out: * ask for a shared writable mapping! * * The page does not need to be reserved. + * + * Usually this function is called from f_op->mmap() handler + * under mm->mmap_sem write-lock, so it can change vma->vm_flags. + * Caller must set VM_MIXEDMAP on vma if it wants to call this + * function from other places, for example from page-fault handler. */ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, struct page *page) @@ -2093,7 +2099,11 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, return -EFAULT; if (!page_count(page)) return -EINVAL; - vma->vm_flags |= VM_INSERTPAGE; + if (!(vma->vm_flags & VM_MIXEDMAP)) { + BUG_ON(down_read_trylock(&vma->vm_mm->mmap_sem)); + BUG_ON(vma->vm_flags & VM_PFNMAP); + vma->vm_flags |= VM_MIXEDMAP; + } return insert_page(vma, addr, page, vma->vm_page_prot); } EXPORT_SYMBOL(vm_insert_page); |