[Qemu-devel] [PATCH v4 0/7] Block Throttle Group Support

[Alberto Garcia <berto@igalia.com>]

A new version of the patchset.

Here was the previous one:

   https://lists.gnu.org/archive/html/qemu-devel/2015-03/msg01990.html

I checked all the things pointed out by Stefan in his comments and I
think all of them are fixed now.

In addition to that I detected and fixed some additional problems.

Here's the detailed list of changes:

- All functions from the ThrottleGroup API now receive a BlockDriverState.
  This simplifies the API a bit more and makes it more consistent.

- The creation/destruction of ThrottleTimers is now handled internally
  when a BlockDriverState is added/removed from a group, since there's
  not much point on keeping them separate. This also hides the timer
  callbacks from the outside, which makes things a bit nicer and
  easier for some of the other changes included in these series.

- bdrv_io_limits_enable() no longer accepts NULL as a valid group name.

- No member of a group can access someone else's throttled_reqs queues
  anymore since there's no safe way to do it. A new (protected) field
  in BDS called pending_reqs serves that purpose now.

- No member of a group can access someone else's timers unless they
  have queued requests. A new field in ThrottleGroup called
  any_timer_armed serves that purpose. This allows changing a BDS's
  AioContext without having to remove it from the group. Otherwise
  it's not safe to call bdrv_set_aio_context().

- After a timer is fired make sure that there was actually a request
  in the queue, and schedule a new one otherwise. This is an unlikely
  corner case that I detected while preparing these series.

- New throttle_group_lock/unlock functions. These are only needed for
  the case of bdrv_swap(), which is not easy to rewrite in a way that
  does not crash without locking the group.

- throttle_group_co_io_limits_intercept() is now marked as a coroutine
  function.

- Documentation updates.

Regards,

Berto

Alberto Garcia (6):
  throttle: Add throttle group infrastructure
  throttle: Add throttle group infrastructure tests
  throttle: Add throttle group support
  throttle: acquire the ThrottleGroup lock in bdrv_swap()
  throttle: add the name of the ThrottleGroup to BlockDeviceInfo
  throttle: Update throttle infrastructure copyright

Benoît Canet (1):
  throttle: Extract timers from ThrottleState into a separate structure

 block.c                         | 101 ++++-----
 block/Makefile.objs             |   1 +
 block/qapi.c                    |   8 +-
 block/throttle-groups.c         | 478 ++++++++++++++++++++++++++++++++++++++++
 blockdev.c                      |  22 +-
 hmp.c                           |  10 +-
 include/block/block.h           |   3 +-
 include/block/block_int.h       |   7 +-
 include/block/throttle-groups.h |  46 ++++
 include/qemu/throttle.h         |  46 ++--
 qapi/block-core.json            |   8 +-
 qemu-options.hx                 |   1 +
 qmp-commands.hx                 |   3 +-
 tests/test-throttle.c           | 119 ++++++----
 util/throttle.c                 |  81 ++++---
 15 files changed, 778 insertions(+), 156 deletions(-)
 create mode 100644 block/throttle-groups.c
 create mode 100644 include/block/throttle-groups.h

-- 
2.1.4