[Qemu-devel] [PATCH v1 0/8] Block Throttle Group Support

["Benoît Canet" <benoit.canet@nodalink.com>]

Hi,

For the user interface I implemented Stefanha's idea proposed in Stuttgart.

For the throttling algorithm I use a cooperative round robin scheduler.

Classical round robin works with a fixed HZ ticks and it's totaly incompatible
with the throttling algorithm.

So the cooperative round robin scheduler is a way for each block device to decide
if a pause must be done and a timer be armed and most important of all which
other block device of the group must resume the work once the timer is fired.

The advantages of this algorigthm are:

-only one timer active at a given time (no more cpu usage than regular throttling)
-no central place didacting the sheduling policy like a didactureship:
 we love collaboration isn't it ?:)
-No need to deal with  incoming queues to collect requests before scheduling
 then with and dispatchs queues
-Compatible with the throttling code with almost no changes
-As you go scheduling

Best regards

Benoît

Benoît Canet (8):
  throttle: Extract timers from ThrottleState into a separate
    ThrottleTimers structure
  throttle: Add throttle group infrastructure
  throttle: Add throttle group infrastructure tests
  throttle: Prepare to have multiple timers for one ThrottleState
  throttle: Add a way to know if throttle_schedule_timer had armed a
    timer
  throttle: Add a way to fire one of the timers asap like a bottom half
  throttle: Add throttle group support
  throttle: Update throttle infrastructure copyright

 block.c                         | 211 ++++++++++++++++++++++++++++++++++-----
 block/Makefile.objs             |   1 +
 block/qapi.c                    |   7 +-
 block/throttle-groups.c         | 212 ++++++++++++++++++++++++++++++++++++++++
 blockdev.c                      |  19 +++-
 hmp.c                           |   4 +-
 include/block/block.h           |   3 +-
 include/block/block_int.h       |   9 +-
 include/block/throttle-groups.h |  45 +++++++++
 include/qemu/throttle.h         |  46 ++++++---
 qapi/block-core.json            |   5 +-
 qemu-options.hx                 |   1 +
 qmp-commands.hx                 |   3 +-
 tests/test-throttle.c           | 137 +++++++++++++++++++-------
 util/throttle.c                 | 107 +++++++++++++-------
 15 files changed, 685 insertions(+), 125 deletions(-)
 create mode 100644 block/throttle-groups.c
 create mode 100644 include/block/throttle-groups.h

-- 
2.1.1