From 76f4afb40fa076ed23fe0ab42c7a768ddb71123f Mon Sep 17 00:00:00 2001 From: Alberto Garcia Date: Mon, 8 Jun 2015 18:17:44 +0200 Subject: throttle: Add throttle group support The throttle group support use a cooperative round robin scheduling algorithm. The principles of the algorithm are simple: - Each BDS of the group is used as a token in a circular way. - The active BDS computes if a wait must be done and arms the right timer. - If a wait must be done the token timer will be armed so the token will become the next active BDS. Signed-off-by: Alberto Garcia Reviewed-by: Stefan Hajnoczi Message-id: f0082a86f3ac01c46170f7eafe2101a92e8fde39.1433779731.git.berto@igalia.com Signed-off-by: Stefan Hajnoczi --- qapi/block-core.json | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) (limited to 'qapi') diff --git a/qapi/block-core.json b/qapi/block-core.json index 8411d4f..3087154 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -1062,6 +1062,27 @@ # # Change I/O throttle limits for a block drive. # +# Since QEMU 2.4, each device with I/O limits is member of a throttle +# group. +# +# If two or more devices are members of the same group, the limits +# will apply to the combined I/O of the whole group in a round-robin +# fashion. Therefore, setting new I/O limits to a device will affect +# the whole group. +# +# The name of the group can be specified using the 'group' parameter. +# If the parameter is unset, it is assumed to be the current group of +# that device. If it's not in any group yet, the name of the device +# will be used as the name for its group. +# +# The 'group' parameter can also be used to move a device to a +# different group. In this case the limits specified in the parameters +# will be applied to the new group only. +# +# I/O limits can be disabled by setting all of them to 0. In this case +# the device will be removed from its group and the rest of its +# members will no be affected. The 'group' parameter is ignored. +# # @device: The name of the device # # @bps: total throughput limit in bytes per second @@ -1090,6 +1111,8 @@ # # @iops_size: #optional an I/O size in bytes (Since 1.7) # +# @group: #optional throttle group name (Since 2.4) +# # Returns: Nothing on success # If @device is not a valid block device, DeviceNotFound # @@ -1101,7 +1124,7 @@ '*bps_max': 'int', '*bps_rd_max': 'int', '*bps_wr_max': 'int', '*iops_max': 'int', '*iops_rd_max': 'int', '*iops_wr_max': 'int', - '*iops_size': 'int' } } + '*iops_size': 'int', '*group': 'str' } } ## # @block-stream: -- cgit v1.1