Messages in this thread | | | Date | Mon, 23 Jun 2008 23:21:09 +0800 | From | "Jeff Chua" <> | Subject | Re: Linux 2.6.26-rc7 |
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On Mon, Jun 23, 2008 at 1:26 AM, Linus Torvalds <torvalds@linux-foundation.org> wrote: > So assuming it's not the XIP fix, you could try this patch instead. It > replaces the (insane) use of VM_LOCKED with VM_SHARED (which is a lot more > meaningful for the case of ZERO_PAGE, but strictly speaking probably > doesn't matter either), and it teaches it about the fact that > non-anonymous pages can be populated not just with the "->fault" handler, > but with "->nopfn" too. > > I really don't think it's due to this (nobody sane really uses '->nopfn'), > but if the XIP disabling patch doesn't make a difference, give it a try.
Linus,
This one fixes the problem! So, it's something strange that VMware is doing, but anyway, glad you fix it!!!
Thanks for the patch.
Jeff.
> (Most of the patch is obviously the fact that I moved the conditionals > into a helper inline function to make the dang thing more readable). The > actual change is trivial. > > Linus > > --- > mm/memory.c | 12 ++++++++++-- > 1 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index 9aefaae..8c5675f 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -1045,6 +1045,15 @@ no_page_table: > return page; > } > > +/* Can we do the FOLL_ANON optimization? */ > +static inline int use_zero_page(struct vm_area_struct *vma) > +{ > + if (vma->vm_flags & VM_SHARED) > + return 0; > + return !vma->vm_ops || > + (!vma->vm_ops->fault && !vma->vm_ops->nopfn); > +} > + > int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, > unsigned long start, int len, int write, int force, > struct page **pages, struct vm_area_struct **vmas) > @@ -1119,8 +1128,7 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, > foll_flags = FOLL_TOUCH; > if (pages) > foll_flags |= FOLL_GET; > - if (!write && !(vma->vm_flags & VM_LOCKED) && > - (!vma->vm_ops || !vma->vm_ops->fault)) > + if (!write && use_zero_page(vma)) > foll_flags |= FOLL_ANON; > > do { >
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