From: Hugh Dickins <hughd@xxxxxxxxxx> Subject: mm: page_vma_mapped_walk(): prettify PVMW_MIGRATION block page_vma_mapped_walk() cleanup: rearrange the !pmd_present() block to follow the same "return not_found, return not_found, return true" pattern as the block above it (note: returning not_found there is never premature, since existence or prior existence of huge pmd guarantees good alignment). Link: https://lkml.kernel.org/r/378c8650-1488-2edf-9647-32a53cf2e21@xxxxxxxxxx Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Reviewed-by: Peter Xu <peterx@xxxxxxxxxx> Cc: Alistair Popple <apopple@xxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Ralph Campbell <rcampbell@xxxxxxxxxx> Cc: Wang Yugui <wangyugui@xxxxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Yang Shi <shy828301@xxxxxxxxx> Cc: Zi Yan <ziy@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_vma_mapped.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) --- a/mm/page_vma_mapped.c~mm-page_vma_mapped_walk-prettify-pvmw_migration-block +++ a/mm/page_vma_mapped.c @@ -198,24 +198,22 @@ restart: if (pmd_page(pmde) != page) return not_found(pvmw); return true; - } else if (!pmd_present(pmde)) { - if (thp_migration_supported()) { - if (!(pvmw->flags & PVMW_MIGRATION)) - return not_found(pvmw); - if (is_migration_entry(pmd_to_swp_entry(pmde))) { - swp_entry_t entry = pmd_to_swp_entry(pmde); + } + if (!pmd_present(pmde)) { + swp_entry_t entry; - if (migration_entry_to_page(entry) != page) - return not_found(pvmw); - return true; - } - } - return not_found(pvmw); - } else { - /* THP pmd was split under us: handle on pte level */ - spin_unlock(pvmw->ptl); - pvmw->ptl = NULL; + if (!thp_migration_supported() || + !(pvmw->flags & PVMW_MIGRATION)) + return not_found(pvmw); + entry = pmd_to_swp_entry(pmde); + if (!is_migration_entry(entry) || + migration_entry_to_page(entry) != page) + return not_found(pvmw); + return true; } + /* THP pmd was split under us: handle on pte level */ + spin_unlock(pvmw->ptl); + pvmw->ptl = NULL; } else if (!pmd_present(pmde)) { /* * If PVMW_SYNC, take and drop THP pmd lock so that we _
