From 684960d46267d6e6443b39ee98b3a95632ba8dc6 Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Tue, 26 Oct 2021 18:23:44 +0200 Subject: file-posix: add `aio-max-batch` option Commit d7ddd0a161 ("linux-aio: limit the batch size using `aio-max-batch` parameter") added a way to limit the batch size of Linux AIO backend for the entire AIO context. The same AIO context can be shared by multiple devices, so latency-sensitive devices may want to limit the batch size even more to avoid increasing latency. For this reason we add the `aio-max-batch` option to the file backend, which will be used by the next commits to limit the size of batches including requests generated by this device. Suggested-by: Kevin Wolf Reviewed-by: Kevin Wolf Signed-off-by: Stefano Garzarella Message-Id: <20211026162346.253081-2-sgarzare@redhat.com> Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- qapi/block-core.json | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'qapi') diff --git a/qapi/block-core.json b/qapi/block-core.json index ce2c135..ea36e00 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -2939,6 +2939,12 @@ # for this device (default: none, forward the commands via SG_IO; # since 2.11) # @aio: AIO backend (default: threads) (since: 2.8) +# @aio-max-batch: maximum number of requests to batch together into a single +# submission in the AIO backend. The smallest value between +# this and the aio-max-batch value of the IOThread object is +# chosen. +# 0 means that the AIO backend will handle it automatically. +# (default: 0, since 6.2) # @locking: whether to enable file locking. If set to 'auto', only enable # when Open File Descriptor (OFD) locking API is available # (default: auto, since 2.10) @@ -2968,6 +2974,7 @@ '*pr-manager': 'str', '*locking': 'OnOffAuto', '*aio': 'BlockdevAioOptions', + '*aio-max-batch': 'int', '*drop-cache': {'type': 'bool', 'if': 'CONFIG_LINUX'}, '*x-check-cache-dropped': { 'type': 'bool', -- cgit v1.1