qemu/hw/block/dataplane
Stefan Hajnoczi 41abca8c39 block: add blk_io_plug_call() API
Introduce a new API for thread-local blk_io_plug() that does not
traverse the block graph. The goal is to make blk_io_plug() multi-queue
friendly.

Instead of having block drivers track whether or not we're in a plugged
section, provide an API that allows them to defer a function call until
we're unplugged: blk_io_plug_call(fn, opaque). If blk_io_plug_call() is
called multiple times with the same fn/opaque pair, then fn() is only
called once at the end of the function - resulting in batching.

This patch introduces the API and changes blk_io_plug()/blk_io_unplug().
blk_io_plug()/blk_io_unplug() no longer require a BlockBackend argument
because the plug state is now thread-local.

Later patches convert block drivers to blk_io_plug_call() and then we
can finally remove .bdrv_co_io_plug() once all block drivers have been
converted.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20230530180959.1108766-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2023-06-01 07:34:03 -04:00
..
meson.build hw/xen: Build PV backend drivers for CONFIG_XEN_BUS 2023-03-07 17:04:30 +00:00
trace-events docs: fix references to docs/devel/tracing.rst 2021-06-02 06:51:09 +02:00
trace.h trace: switch position of headers to what Meson requires 2020-08-21 06:18:24 -04:00
virtio-blk.c virtio-blk: implement BlockDevOps->drained_begin() 2023-05-30 17:32:02 +02:00
virtio-blk.h hw/block: Fix the return type 2017-12-19 09:25:28 +00:00
xen-block.c block: add blk_io_plug_call() API 2023-06-01 07:34:03 -04:00
xen-block.h xen-block: implement BlockDevOps->drained_begin() 2023-05-30 17:32:02 +02:00