On 2021/3/13 3:58, Mike Kravetz wrote: > On 3/8/21 3:28 AM, Miaohe Lin wrote: >> Rework the error handling code when alloc_huge_page() failed to remove some >> duplicated code and simplify the code slightly. >> >> Signed-off-by: Miaohe Lin <[email protected]> >> --- >> mm/hugetlb.c | 9 +++------ >> 1 file changed, 3 insertions(+), 6 deletions(-) >> >> diff --git a/mm/hugetlb.c b/mm/hugetlb.c >> index 695603071f2c..69b8de866a24 100644 >> --- a/mm/hugetlb.c >> +++ b/mm/hugetlb.c >> @@ -4337,13 +4337,10 @@ static vm_fault_t hugetlb_no_page(struct mm_struct >> *mm, >> * sure there really is no pte entry. >> */ >> ptl = huge_pte_lock(h, mm, ptep); >> - if (!huge_pte_none(huge_ptep_get(ptep))) { >> - ret = 0; >> - spin_unlock(ptl); >> - goto out; >> - } >> + ret = 0; >> + if (huge_pte_none(huge_ptep_get(ptep))) >> + ret = vmf_error(PTR_ERR(page)); > > This new code is simpler. > > The !huge_pte_none() catches an unlikely race. IMO, the existing code > made that very clear. Would have been even more clear with an unlikely > modifier. In any case, the lengthy comment above this code makes it > clear why the check is there. Code changes are fine. >
Yep, the lengthy comment above this code makes it much clear why we need the check. Thanks for carefully review! :) > Reviewed-by: Mike Kravetz <[email protected]> >
