Howdy Kosaki-san, Thanks for your time over this one :) On Mon, May 20, 2013 at 08:55:33PM -0400, KOSAKI Motohiro wrote: > (5/20/13 8:04 PM), Rafael Aquini wrote: > > Intruduce a new flag to make page-cluster fine-grained discards while swapping > > conditional, as they can be considered detrimental to some setups. However, > > keep allowing batched discards at sys_swapon() time, when enabled by the > > system administrator. > > > > Signed-off-by: Rafael Aquini <aquini@xxxxxxxxxx> > > --- > > include/linux/swap.h | 8 +++++--- > > mm/swapfile.c | 12 ++++++++---- > > 2 files changed, 13 insertions(+), 7 deletions(-) > > > > diff --git a/include/linux/swap.h b/include/linux/swap.h > > index 1701ce4..ab2e742 100644 > > --- a/include/linux/swap.h > > +++ b/include/linux/swap.h > > @@ -19,10 +19,11 @@ struct bio; > > #define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */ > > #define SWAP_FLAG_PRIO_MASK 0x7fff > > #define SWAP_FLAG_PRIO_SHIFT 0 > > -#define SWAP_FLAG_DISCARD 0x10000 /* discard swap cluster after use */ > > +#define SWAP_FLAG_DISCARD 0x10000 /* enable discard for swap areas */ > > +#define SWAP_FLAG_DISCARD_CLUSTER 0x20000 /* discard swap clusters after use */ > > From point of backward compatibility view, 0x10000 should be disable both discarding > when mount and when IO. I think you mean 0x10000 should be enable both here, then. That's a nice catch. I'll try to think a way to accomplish it in a simple fashion. > And, introducing new two flags, enable mount time discard and enable IO time discard. > > IOW, Please consider newer kernel and older swapon(8) conbination. > Other than that, looks good to me. > > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>