[PATCH 0/2] btrfs: reduce extent map lookup overhead for data write

[Qu Wenruo <wqu@suse.com>]

Unlike data read path, which use cached extent map to reduce overhead,
data write path always do the extent map lookup no matter what.

So this patchset will improve the situation by:

- Move em_cached into bio_ctrl
  Since the lifespan of them is the same, it's a perfect match.

- Make data write path to use bio_ctrl::em_cached

Unfortunately since my last relocation, I no longer have any dedicated
storage attached to my VMs (my laptop only has one NVME slot, and my main
workhorse aarch64 board only has one NVME attached either).

So no benchmark yet, and any extra benchmark would be very appreciated.

Qu Wenruo (2):
  btrfs: introduce extent_map::em_cached member
  btrfs: utilize cached extent map for data writeback

 fs/btrfs/extent_io.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

-- 
2.45.2