diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2020-06-17 14:22:01 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2020-06-23 15:46:08 +0100 |
| commit | 7838c67f22a81fcf669785cd6c0876438422071a (patch) | |
| tree | 55d08313439c1728cd0883cf2c924213a861701c /block/trace-events | |
| parent | b75fd5f55467307a6e367bc349a8ea6ce30d8a1c (diff) | |
block/nvme: support nested aio_poll()
QEMU block drivers are supposed to support aio_poll() from I/O
completion callback functions. This means completion processing must be
re-entrant.
The standard approach is to schedule a BH during completion processing
and cancel it at the end of processing. If aio_poll() is invoked by a
callback function then the BH will run. The BH continues the suspended
completion processing.
All of this means that request A's cb() can synchronously wait for
request B to complete. Previously the nvme block driver would hang
because it didn't process completions from nested aio_poll().
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Message-id: 20200617132201.1832152-8-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/trace-events')
| -rw-r--r-- | block/trace-events | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/trace-events b/block/trace-events index 29dff8881c..dbe76a7613 100644 --- a/block/trace-events +++ b/block/trace-events @@ -158,7 +158,7 @@ nvme_kick(void *s, int queue) "s %p queue %d" nvme_dma_flush_queue_wait(void *s) "s %p" nvme_error(int cmd_specific, int sq_head, int sqid, int cid, int status) "cmd_specific %d sq_head %d sqid %d cid %d status 0x%x" nvme_process_completion(void *s, int index, int inflight) "s %p queue %d inflight %d" -nvme_process_completion_queue_busy(void *s, int index) "s %p queue %d" +nvme_process_completion_queue_plugged(void *s, int index) "s %p queue %d" nvme_complete_command(void *s, int index, int cid) "s %p queue %d cid %d" nvme_submit_command(void *s, int index, int cid) "s %p queue %d cid %d" nvme_submit_command_raw(int c0, int c1, int c2, int c3, int c4, int c5, int c6, int c7) "%02x %02x %02x %02x %02x %02x %02x %02x" |