Re: [PATCH v3 1/4] mm/swapfile: use percpu_ref to serialize against concurrent swapoff

Miaohe Lin writes: > Using current get/put_swap_device() to guard against concurrent swapoff > for some swap ops, e.g. swap_readpage(), looks terrible because they > might take really long time. This patch adds the percpu_ref support to > serialize against concurrent swapoff. Also we remove the

[PATCH v3 1/4] mm/swapfile: use percpu_ref to serialize against concurrent swapoff

Using current get/put_swap_device() to guard against concurrent swapoff for some swap ops, e.g. swap_readpage(), looks terrible because they might take really long time. This patch adds the percpu_ref support to serialize against concurrent swapoff. Also we remove the SWP_VALID flag because it's