[Qemu-devel] [PATCH V4 0/3] qemu: Threadlets: A generic task offloading framework

[Gautham R Shenoy <ego@in.ibm.com>]

Hi,

This is the v4 of the patch-series to have a generic asynchronous task
offloading framework (called threadlets) within qemu.

V3 can be found here:
http://lists.gnu.org/archive/html/qemu-devel/2010-06/index.html

Changes from V3:
=====================================================================
- Did away with the qemu-thread wrappers for handling pthread_attr_t type
  following review comments for V3.

- Added qemu-thread wrappers for pthread_barrier_init() and
  pthread_barrier_wait().

- Added a flush_threadlet_queue() helper which allows the caller to wait till
  all the queued tasks have finished processing.

- Added a global queue that can be used by most subsystems to offload tasks. The
  flexibility to allow individual subsystems to create their private queue with
  associated thread-pool has been retained.

- Fixed the Copyrights in the newly introduced file to reflect the copyrights of
  the borrowed code.

- Renamed the helper functions to reflect their use. Added comments for each of
  the helpers.

- Typedef'd the structs to adhere to the qemu coding style.

Description
=====================================================================
This patch series decouples the asynchronous threading framework
implementation from posix-aio-compat.c to implement a generic asynchronous
task offloading threading framework called threadlets which can be used
by other subsystems within QEMU.

Currently within QEMU, the AIO subsystem (paio) creates a bunch of
asynchronous threads to offload any blocking operations so that
the vcpu threads and the IO thread can go back to servicing any
other guest requests.

This offloading framework can be used by subsystems such as virtio-9p,
Asynchronous encoding for vnc-server, so that the vcpu thread can offload
blocking operations on to the asynchronous threads and resume servicing
any other guest requests. The asynchronous threads, after
finishing the blocking operations can then transfer the control over
to the IO thread so that the latter can handle the post_blocking_operation().

The patch series passed fsstress test without any issues.

Could it be considered for inclusion ?

---

Aneesh Kumar K.V (1):
      qemu: Generic task offloading framework: threadlets

Gautham R Shenoy (2):
      qemu: Add qemu-barrier support to qemu-thread framework.
      qemu: Convert AIO code to use threadlets.


 Makefile.objs      |    3 +
 async-work.c       |  186 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 async-work.h       |   69 +++++++++++++++++++
 posix-aio-compat.c |  152 +++++++-----------------------------------
 qemu-thread.c      |   23 ++++++
 qemu-thread.h      |    9 +++
 6 files changed, 313 insertions(+), 129 deletions(-)
 create mode 100644 async-work.c
 create mode 100644 async-work.h

-- 
Thanks and Regards
gautham.