On Thu, Jun 21, 2018 at 8:55 PM Huang, Ying <[email protected]> wrote: > > From: Huang Ying <[email protected]> > > Previously, the PMD swap operations are only enabled for > CONFIG_ARCH_ENABLE_THP_MIGRATION. Because they are only used by the > THP migration support. We will support PMD swap mapping to the huge > swap cluster and swapin the THP as a whole. That will be enabled via > CONFIG_THP_SWAP and needs these PMD swap operations. So enable the > PMD swap operations for CONFIG_THP_SWAP too. > > Signed-off-by: "Huang, Ying" <[email protected]> > Cc: "Kirill A. Shutemov" <[email protected]> > Cc: Andrea Arcangeli <[email protected]> > Cc: Michal Hocko <[email protected]> > Cc: Johannes Weiner <[email protected]> > Cc: Shaohua Li <[email protected]> > Cc: Hugh Dickins <[email protected]> > Cc: Minchan Kim <[email protected]> > Cc: Rik van Riel <[email protected]> > Cc: Dave Hansen <[email protected]> > Cc: Naoya Horiguchi <[email protected]> > Cc: Zi Yan <[email protected]> > Cc: Daniel Jordan <[email protected]> > --- > arch/x86/include/asm/pgtable.h | 2 +- > include/asm-generic/pgtable.h | 2 +- > include/linux/swapops.h | 44 > ++++++++++++++++++++++-------------------- > 3 files changed, 25 insertions(+), 23 deletions(-) > > diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h > index 99ecde23c3ec..13bf58838daf 100644 > --- a/arch/x86/include/asm/pgtable.h > +++ b/arch/x86/include/asm/pgtable.h > @@ -1224,7 +1224,7 @@ static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) > return pte_clear_flags(pte, _PAGE_SWP_SOFT_DIRTY); > } > > -#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION > +#if defined(CONFIG_ARCH_ENABLE_THP_MIGRATION) || defined(CONFIG_THP_SWAP)
How about introducing a new config symbol representing the common infrastructure between the two and have them select that symbol. Would that also allow us to clean up the usage of CONFIG_ARCH_ENABLE_THP_MIGRATION in fs/proc/task_mmu.c? In other words, what's the point of having nice ifdef'd alternatives in header files when ifdefs are still showing up in C files, all of it should be optionally determined by header files.
