Re: [Qemu-devel] [RFC V2 0/8] Throttle group cooperative round robin scheduling

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

On Wed, Aug 13, 2014 at 04:23:51PM +0200, Benoît Canet wrote:
> Hi,
> 
> Here is my current wip on the throttle group support.
> 
> 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                      |  18 +++-
>  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, 684 insertions(+), 125 deletions(-)
>  create mode 100644 block/throttle-groups.c
>  create mode 100644 include/block/throttle-groups.h
> 
> -- 
> 2.1.0.rc1
> 

ping