On 09/07/2016 10:16 PM, Huang, Ying wrote: > From: Huang Ying <ying.hu...@intel.com> > > With this patch, a THP (Transparent Huge Page) can be added/deleted > to/from the swap cache as a set of sub-pages (512 on x86_64). > > This will be used for the THP (Transparent Huge Page) swap support. > Where one THP may be added/delted to/from the swap cache. This will > batch the swap cache operations to reduce the lock acquire/release times > for the THP swap too. > > Cc: Hugh Dickins <hu...@google.com> > Cc: Shaohua Li <s...@kernel.org> > Cc: Minchan Kim <minc...@kernel.org> > Cc: Rik van Riel <r...@redhat.com> > Cc: Andrea Arcangeli <aarca...@redhat.com> > Cc: Kirill A. Shutemov <kirill.shute...@linux.intel.com> > Signed-off-by: "Huang, Ying" <ying.hu...@intel.com> > --- > include/linux/page-flags.h | 2 +- > mm/swap_state.c | 57 > +++++++++++++++++++++++++++++++--------------- > 2 files changed, 40 insertions(+), 19 deletions(-) > > diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h > index 74e4dda..f5bcbea 100644 > --- a/include/linux/page-flags.h > +++ b/include/linux/page-flags.h > @@ -314,7 +314,7 @@ PAGEFLAG_FALSE(HighMem) > #endif > > #ifdef CONFIG_SWAP > -PAGEFLAG(SwapCache, swapcache, PF_NO_COMPOUND) > +PAGEFLAG(SwapCache, swapcache, PF_NO_TAIL)
What is the reason for this change ? The commit message does not seem to explain.
