On Tue, May 30, 2023 at 02:09:58PM -0400, Stefan Hajnoczi wrote:
Stop using the .bdrv_co_io_plug() API because it is not multi-queue
block layer friendly. Use the new blk_io_plug_call() API to batch I/O
submission instead.
Note that a dev_max_batch check is dropped in laio_io_unplug() because
the semantics of unplug_fn() are different from .bdrv_co_unplug():
1. unplug_fn() is only called when the last blk_io_unplug() call occurs,
not every time blk_io_unplug() is called.
2. unplug_fn() is per-thread, not per-BlockDriverState, so there is no
way to get per-BlockDriverState fields like dev_max_batch.
Therefore this condition cannot be moved to laio_unplug_fn(). It is not
obvious that this condition affects performance in practice, so I am
removing it instead of trying to come up with a more complex mechanism
to preserve the condition.
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
---
include/block/raw-aio.h | 7 -------
block/file-posix.c | 28 ----------------------------
block/linux-aio.c | 41 +++++++++++------------------------------
3 files changed, 11 insertions(+), 65 deletions(-)
LGTM!
Reviewed-by: Stefano Garzarella <sgarz...@redhat.com>
