On 2020-04-23 at 20:49 Li Xinhai wrote: >When huge_pte_offset() is called, the parameter sz can only be PUD_SIZE >or PMD_SIZE. >If sz is PUD_SIZE and code can reach pud, then *pud must be none, or >normal hugetlb entry, or non-present (migration or hwpoisoned) hugetlb >entry, and we can directly return pud. >When sz is PMD_SIZE, pud must be none or present, and if code can reach >pmd, we can directly return pmd. > >So, after this patch, the code is simplified by first check on the >parameter sz, and avoid unnecessary checks in current code. > >Signed-off-by: Li Xinhai <lixinhai.lxh@xxxxxxxxx> >Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> >Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Since this huge_pte_offset() is under CONFIG_ARCH_WANT_GENERAL_HUGETLB, I only have chance to test with x86_64, but the logical should hold for all other cases which using this general implementation. The exsiting code path was introduced by commit 9b19df292c6 (mm/hugetlb.c: make huge_pte_offset() consistent and document behaviour), and the sematics is maintained after current patch applied.
