qemu/include/block
Paolo Bonzini 0c330a734b aio: introduce aio_co_schedule and aio_co_wake
aio_co_wake provides the infrastructure to start a coroutine on a "home"
AioContext.  It will be used by CoMutex and CoQueue, so that coroutines
don't jump from one context to another when they go to sleep on a
mutex or waitqueue.  However, it can also be used as a more efficient
alternative to one-shot bottom halves, and saves the effort of tracking
which AioContext a coroutine is running on.

aio_co_schedule is the part of aio_co_wake that starts a coroutine
on a remove AioContext, but it is also useful to implement e.g.
bdrv_set_aio_context callbacks.

The implementation of aio_co_schedule is based on a lock-free
multiple-producer, single-consumer queue.  The multiple producers use
cmpxchg to add to a LIFO stack.  The consumer (a per-AioContext bottom
half) grabs all items added so far, inverts the list to make it FIFO,
and goes through it one item at a time until it's empty.  The data
structure was inspired by OSv, which uses it in the very code we'll
"port" to QEMU for the thread-safe CoMutex.

Most of the new code is really tests.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213135235.12274-3-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21 11:14:07 +00:00
..
accounting.h Use scripts/clean-includes to drop redundant qemu/typedefs.h 2016-03-22 22:20:16 +01:00
aio.h aio: introduce aio_co_schedule and aio_co_wake 2017-02-21 11:14:07 +00:00
block_backup.h Backup: export interfaces for extra serialization 2016-09-13 11:00:56 +01:00
block_int.h block: get rid of bdrv_io_unplugged_begin/end 2017-01-16 13:25:17 +00:00
block.h block: Fix target variable of BLKSECTGET ioctl 2017-01-27 18:07:31 +01:00
blockjob_int.h blockjob: add .start field 2016-11-14 22:47:34 -05:00
blockjob.h blockjob: add block_job_start 2016-11-14 22:47:34 -05:00
dirty-bitmap.h block: More operations for meta dirty bitmap 2016-10-24 17:56:07 +02:00
nbd.h nbd: Implement NBD_CMD_WRITE_ZEROES on server 2016-11-02 09:28:56 +01:00
qapi.h block/qapi: Use blk_enable_write_cache() 2016-03-30 12:16:02 +02:00
raw-aio.h linux-aio: share one LinuxAioState within an AioContext 2016-07-18 15:09:31 +01:00
scsi.h * SCSI scanner support 2016-07-14 13:44:06 +01:00
snapshot.h include: Clean up includes 2016-02-23 12:43:05 +00:00
thread-pool.h Clean up decorations and whitespace around header guards 2016-07-12 16:20:46 +02:00
throttle-groups.h block: Move I/O throttling configuration functions to BlockBackend 2016-05-19 16:45:30 +02:00
write-threshold.h Use scripts/clean-includes to drop redundant qemu/typedefs.h 2016-03-22 22:20:16 +01:00