On 09/07/2016 10:16 PM, Huang, Ying wrote: > From: Huang Ying <[email protected]> > > 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 <[email protected]> > Cc: Shaohua Li <[email protected]> > Cc: Minchan Kim <[email protected]> > Cc: Rik van Riel <[email protected]> > Cc: Andrea Arcangeli <[email protected]> > Cc: Kirill A. Shutemov <[email protected]> > Signed-off-by: "Huang, Ying" <[email protected]> > --- > 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.
