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| author | Stefano Garzarella | 2021-07-21 11:42:10 +0200 |
|---|---|---|
| committer | Stefan Hajnoczi | 2021-07-21 14:47:50 +0200 |
| commit | 1793ad0247cad35db1ebbc04fbea0446c30a27ca (patch) | |
| tree | 3b26eff84f99fa68fcef95a40b52a3aa48ce9f72 /qapi | |
| parent | iothread: generalize iothread_set_param/iothread_get_param (diff) | |
| download | qemu-1793ad0247cad35db1ebbc04fbea0446c30a27ca.tar.gz qemu-1793ad0247cad35db1ebbc04fbea0446c30a27ca.tar.xz qemu-1793ad0247cad35db1ebbc04fbea0446c30a27ca.zip | |
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 'qapi')
| -rw-r--r-- | qapi/misc.json | 6 | ||||
| -rw-r--r-- | qapi/qom.json | 7 |
2 files changed, 11 insertions, 2 deletions
diff --git a/qapi/misc.json b/qapi/misc.json index 156f98203e..5c2ca3b556 100644 --- a/qapi/misc.json +++ b/qapi/misc.json @@ -86,6 +86,9 @@ # @poll-shrink: how many ns will be removed from polling time, 0 means that # it's not configured (since 2.9) # +# @aio-max-batch: maximum number of requests in a batch for the AIO engine, +# 0 means that the engine will use its default (since 6.1) +# # Since: 2.0 ## { 'struct': 'IOThreadInfo', @@ -93,7 +96,8 @@ 'thread-id': 'int', 'poll-max-ns': 'int', 'poll-grow': 'int', - 'poll-shrink': 'int' } } + 'poll-shrink': 'int', + 'aio-max-batch': 'int' } } ## # @query-iothreads: diff --git a/qapi/qom.json b/qapi/qom.json index 652be317b8..6d5f4a88e6 100644 --- a/qapi/qom.json +++ b/qapi/qom.json @@ -516,12 +516,17 @@ # algorithm detects it is spending too long polling without # encountering events. 0 selects a default behaviour (default: 0) # +# @aio-max-batch: maximum number of requests in a batch for the AIO engine, +# 0 means that the engine will use its default +# (default:0, since 6.1) +# # Since: 2.0 ## { 'struct': 'IothreadProperties', 'data': { '*poll-max-ns': 'int', '*poll-grow': 'int', - '*poll-shrink': 'int' } } + '*poll-shrink': 'int', + '*aio-max-batch': 'int' } } ## # @MemoryBackendProperties: |