Messages in this thread | | | Subject | Re: [PATCH] mm: gup: remove FOLL_SPLIT | From | John Hubbard <> | Date | Tue, 30 Mar 2021 00:08:34 -0700 |
| |
On 3/29/21 12:38 PM, Yang Shi wrote: > Since commit 5a52c9df62b4 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT") > and commit ba925fa35057 ("s390/gmap: improve THP splitting") FOLL_SPLIT > has not been used anymore. Remove the dead code. > > Signed-off-by: Yang Shi <shy828301@gmail.com> > --- > include/linux/mm.h | 1 - > mm/gup.c | 28 ++-------------------------- > 2 files changed, 2 insertions(+), 27 deletions(-) >
Looks nice.
As long as I'm running git grep here, there is one more search hit that should also be fixed up, as part of a "remove FOLL_SPLIT" patch:
git grep -nw FOLL_SPLIT Documentation/vm/transhuge.rst:57:follow_page, the FOLL_SPLIT bit can be specified as a parameter to
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
thanks, -- John Hubbard NVIDIA
> diff --git a/include/linux/mm.h b/include/linux/mm.h > index 8ba434287387..3568836841f9 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -2780,7 +2780,6 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, > #define FOLL_NOWAIT 0x20 /* if a disk transfer is needed, start the IO > * and return without waiting upon it */ > #define FOLL_POPULATE 0x40 /* fault in page */ > -#define FOLL_SPLIT 0x80 /* don't return transhuge pages, split them */ > #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */ > #define FOLL_NUMA 0x200 /* force NUMA hinting page fault */ > #define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */ > diff --git a/mm/gup.c b/mm/gup.c > index e40579624f10..f3d45a8f18ae 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -435,18 +435,6 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, > } > } > > - if (flags & FOLL_SPLIT && PageTransCompound(page)) { > - get_page(page); > - pte_unmap_unlock(ptep, ptl); > - lock_page(page); > - ret = split_huge_page(page); > - unlock_page(page); > - put_page(page); > - if (ret) > - return ERR_PTR(ret); > - goto retry; > - } > - > /* try_grab_page() does nothing unless FOLL_GET or FOLL_PIN is set. */ > if (unlikely(!try_grab_page(page, flags))) { > page = ERR_PTR(-ENOMEM); > @@ -591,7 +579,7 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma, > spin_unlock(ptl); > return follow_page_pte(vma, address, pmd, flags, &ctx->pgmap); > } > - if (flags & (FOLL_SPLIT | FOLL_SPLIT_PMD)) { > + if (flags & FOLL_SPLIT_PMD) { > int ret; > page = pmd_page(*pmd); > if (is_huge_zero_page(page)) { > @@ -600,19 +588,7 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma, > split_huge_pmd(vma, pmd, address); > if (pmd_trans_unstable(pmd)) > ret = -EBUSY; > - } else if (flags & FOLL_SPLIT) { > - if (unlikely(!try_get_page(page))) { > - spin_unlock(ptl); > - return ERR_PTR(-ENOMEM); > - } > - spin_unlock(ptl); > - lock_page(page); > - ret = split_huge_page(page); > - unlock_page(page); > - put_page(page); > - if (pmd_none(*pmd)) > - return no_page_table(vma, flags); > - } else { /* flags & FOLL_SPLIT_PMD */ > + } else { > spin_unlock(ptl); > split_huge_pmd(vma, pmd, address); > ret = pte_alloc(mm, pmd) ? -ENOMEM : 0; >
| |