On 2025/4/3 1:43, Eric Biggers wrote:
On Wed, Apr 02, 2025 at 03:09:34PM +0800, LongPing Wei wrote:
1. call blk_flush_plug when cache hit as the address of the subsequent
bio is no longer contiguous with the previous bio;
2. skip cond_resched when ioprio class is rt;
Signed-off-by: LongPing Wei <weilongping@xxxxxxxx>
---
drivers/md/dm-bufio.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
Looks fine:
Reviewed-by: Eric Biggers <ebiggers@xxxxxxxxxx>
But I do think the prefetching should be reworked to be along the lines of what
I suggested here:
https://lore.kernel.org/dm-devel/20250327170524.GF1425@sol.localdomain/
Any chance you're interested in helping with that?
How about calling verity_prefetch_io directly in verity_map only when
use_bh_wq return true for this dm io? The size of dm io may be a greate
number as dm-verity doesn't set a max io length. Mikulas once mentioned
that there was a problem that caused him to give up doing so. Has that
issue been fixed?
It also *might* be the case that the prefetching is no longer helpful and should
just be removed. Especially if dm-verity will start prefetching the whole hash
tree anyway, as your other patch does.
It seems that we cannot just removed the prefetching in verity_map as
the cahche in dm-bufio may be shrinked.
- Eric
LongPing
