Searched hist:"7838 c67f" (Results 1 – 2 of 2) sorted by relevance
| /qemu/block/ |
| H A D | trace-events | 7838c67f Wed Jun 17 13:22:01 GMT 2020 Stefan Hajnoczi <stefanha@redhat.com> 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>
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| H A D | nvme.c | 7838c67f Wed Jun 17 13:22:01 GMT 2020 Stefan Hajnoczi <stefanha@redhat.com> 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>
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