On Sat, Jan 09, 2016 at 04:54:59PM -0800, Hugh Dickins wrote: > Swapoff after swapping hangs on the G5, when CONFIG_CHECKPOINT_RESTORE=y > but CONFIG_MEM_SOFT_DIRTY is not set. That's because the non-zero > _PAGE_SWP_SOFT_DIRTY bit, added by CONFIG_HAVE_ARCH_SOFT_DIRTY=y, is not > discounted when CONFIG_MEM_SOFT_DIRTY is not set: so swap ptes cannot be > recognized. > > (I suspect that the peculiar dependence of HAVE_ARCH_SOFT_DIRTY on > CHECKPOINT_RESTORE in arch/powerpc/Kconfig comes from an incomplete > attempt to solve this problem.) > > It's true that the relationship between CONFIG_HAVE_ARCH_SOFT_DIRTY and > and CONFIG_MEM_SOFT_DIRTY is too confusing, and it's true that swapoff > should be made more robust; but nevertheless, fix up the powerpc ifdefs > as x86_64 and s390 (which met the same problem) have them, defining the > bits as 0 if CONFIG_MEM_SOFT_DIRTY is not set. > > Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Reviewed-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx> Thank you, Hugh! -- 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>