Re: [Qemu-devel] [PATCH v4 0/3] qemu-timer: make qemu_timer_mod_ns() and qemu_timer_del() thread-safe

[Stefan Hajnoczi <stefanha@gmail.com>]

On Thu, Sep 12, 2013 at 11:02:17AM +0200, Stefan Hajnoczi wrote:
> v4:
>  * Rebased & retested for easy review and merge
>  * No code changes
> 
> v3:
>  * Squashed Paolo's fixes and added his patch to avoid locking in timer_pending()
> 
> v2:
>  * Rebased onto qemu.git/master following the merge of Alex's AioContext timers
> 
> The purpose of these patches is to eventually allow device models to set and
> cancel timers without holding the global mutex.  When the device model runs in
> a vcpu thread and the iothread processes timers, the
> QEMUTimerList->active_timers must be protected from concurrent access.
> 
> Patch 1 is a clean-up.
> 
> Patch 2 is the entire change needed to protect ->active_timers.
> 
> Patch 3 makes timer_pending() run without a lock.
> 
> Paolo Bonzini (1):
>   qemu-timer: do not take the lock in timer_pending
> 
> Stefan Hajnoczi (2):
>   qemu-timer: drop outdated signal safety comments
>   qemu-timer: make qemu_timer_mod_ns() and qemu_timer_del() thread-safe
> 
>  include/qemu/timer.h | 17 ++++++++++
>  qemu-timer.c         | 92 ++++++++++++++++++++++++++++++++++++----------------
>  2 files changed, 81 insertions(+), 28 deletions(-)

Applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan