Re: [PATCHv4 23/39] thp: wait_split_huge_page(): serialize overi_mmap_mutex too

From: Kirill A. Shutemov
Date: Mon Jun 03 2013 - 12:08:50 EST


Dave Hansen wrote:
>
> On 06/03/2013 08:02 AM, Kirill A. Shutemov wrote:
> > Dave Hansen wrote:
> >> On 05/11/2013 06:23 PM, Kirill A. Shutemov wrote:
> >>> From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx
> >>> -#define wait_split_huge_page(__anon_vma, __pmd) \
> >>> +#define wait_split_huge_page(__vma, __pmd) \
> >>> do { \
> >>> pmd_t *____pmd = (__pmd); \
> >>> - anon_vma_lock_write(__anon_vma); \
> >>> - anon_vma_unlock_write(__anon_vma); \
> >>> + struct address_space *__mapping = \
> >>> + vma->vm_file->f_mapping; \
> >>> + struct anon_vma *__anon_vma = (__vma)->anon_vma; \
> >>> + if (__mapping) \
> >>> + mutex_lock(&__mapping->i_mmap_mutex); \
> >>> + if (__anon_vma) { \
> >>> + anon_vma_lock_write(__anon_vma); \
> >>> + anon_vma_unlock_write(__anon_vma); \
> >>> + } \
> >>> + if (__mapping) \
> >>> + mutex_unlock(&__mapping->i_mmap_mutex); \
> >>> BUG_ON(pmd_trans_splitting(*____pmd) || \
> >>> pmd_trans_huge(*____pmd)); \
> >>> } while (0)
> ...
> >> Could you also describe the lengths to which you've gone to try and keep
> >> this macro from growing in to any larger of an abomination. Is it truly
> >> _impossible_ to turn this in to a normal function? Or will it simply be
> >> a larger amount of work that you can do right now? What would it take?
> >
> > Okay, I've tried once again. The patch is below. It looks too invasive for
> > me. What do you think?
>
> That patch looks great to me, actually. It really looks to just be
> superficially moving code around. The diffstat is even too:

One of blocker I see is new dependency <linux/mm.h> -> <linux/fs.h>.
It makes header files nightmare worse.

--
Kirill A. Shutemov
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