md/md-bitmap: add a new helper to unplug bitmap asynchrously

If bitmap is enabled, bitmap must update before submitting write io, this
is why unplug callback must move these io to 'conf->pending_io_list' if
'current->bio_list' is not empty, which will suffer performance
degradation.

A new helper md_bitmap_unplug_async() is introduced to submit bitmap io
in a kworker, so that submit bitmap io in raid10_unplug() doesn't require
that 'current->bio_list' is empty.

This patch prepare to limit the number of plugged bio.

Signed-off-by: Yu Kuai <[email protected]>
Signed-off-by: Song Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

0 files changed, 0 insertions, 0 deletions