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 <shy828...@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 <jhubb...@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;
