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| author | Stefano Garzarella <sgarzare@redhat.com> | 2021-07-21 11:42:10 +0200 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2021-07-21 13:47:50 +0100 |
| commit | 1793ad0247cad35db1ebbc04fbea0446c30a27ca (patch) | |
| tree | 3b26eff84f99fa68fcef95a40b52a3aa48ce9f72 /include/block | |
| parent | 0445409d7497bededa1047f0d8298b0d4bb3b1a3 (diff) | |
| download | qemu-1793ad0247cad35db1ebbc04fbea0446c30a27ca.zip qemu-1793ad0247cad35db1ebbc04fbea0446c30a27ca.tar.gz qemu-1793ad0247cad35db1ebbc04fbea0446c30a27ca.tar.bz2 | |
iothread: add aio-max-batch parameter
The `aio-max-batch` parameter will be propagated to AIO engines
and it will be used to control the maximum number of queued requests.
When there are in queue a number of requests equal to `aio-max-batch`,
the engine invokes the system call to forward the requests to the kernel.
This parameter allows us to control the maximum batch size to reduce
the latency that requests might accumulate while queued in the AIO
engine queue.
If `aio-max-batch` is equal to 0 (default value), the AIO engine will
use its default maximum batch size value.
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20210721094211.69853-3-sgarzare@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'include/block')
| -rw-r--r-- | include/block/aio.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/block/aio.h b/include/block/aio.h index 807edce..47fbe9d 100644 --- a/include/block/aio.h +++ b/include/block/aio.h @@ -232,6 +232,9 @@ struct AioContext { int64_t poll_grow; /* polling time growth factor */ int64_t poll_shrink; /* polling time shrink factor */ + /* AIO engine parameters */ + int64_t aio_max_batch; /* maximum number of requests in a batch */ + /* * List of handlers participating in userspace polling. Protected by * ctx->list_lock. Iterated and modified mostly by the event loop thread @@ -755,4 +758,13 @@ void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns, int64_t grow, int64_t shrink, Error **errp); +/** + * aio_context_set_aio_params: + * @ctx: the aio context + * @max_batch: maximum number of requests in a batch, 0 means that the + * engine will use its default + */ +void aio_context_set_aio_params(AioContext *ctx, int64_t max_batch, + Error **errp); + #endif |