glusterfs.git/contrib/qemu/coroutine-ucontext.c, branch v3.8.8 qemu-block: deprecated/defunct, remove from tree 2016-03-07T11:34:59+00:00 Kaleb S KEITHLEY kkeithle@redhat.com 2016-02-18T16:21:12+00:00 6860968c3adaf2e8c3cb51124bbdfccef74beeb9 qemu-block xlator is not used by anyone, or so I'm told. It's also substantially out of date. There's little reason to keep it in our sources. (And FedoraProject doesn't like bundled software either.) Change-Id: I4aeb2fdfd962ec6d93de6bae126874121272220a Signed-off-by: Kaleb S KEITHLEY <kkeithle@redhat.com> Reviewed-on: http://review.gluster.org/13473 Smoke: Gluster Build System <jenkins@build.gluster.com> CentOS-regression: Gluster Build System <jenkins@build.gluster.com> NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org> Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com> Reviewed-by: Jeff Darcy <jdarcy@redhat.com> 
qemu-block xlator is not used by anyone, or so I'm told.

It's also substantially out of date. There's little reason to keep
it in our sources. (And FedoraProject doesn't like bundled software
either.)

Change-Id: I4aeb2fdfd962ec6d93de6bae126874121272220a
Signed-off-by: Kaleb S KEITHLEY <kkeithle@redhat.com>
Reviewed-on: http://review.gluster.org/13473
Smoke: Gluster Build System <jenkins@build.gluster.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
features/qemu-block: simplify coroutine model to use single synctask, ucontext 2013-11-11T07:45:46+00:00 Brian Foster bfoster@redhat.com 2013-10-18T11:36:38+00:00 b06ecde2997b72a41b2f2d25d55e61d30ea46bc2 The current coroutine model, mapping synctasks 1-1 with qemu internal Coroutines, has some unresolved raciness issues. This problem usually manifests as lifecycle mismatches between top-level (gluster created) synctasks and the subsequently created internal coroutines from that context. Qemu's internal queueing (and locking) can cause situations where the top-level synctask is destroyed before the internal scheduler has released references to memory, leading to use after free crashes and asserts. Simplify the coroutine model to use a single synctask as a coroutine processor and rely on the existing native ucontext coroutine implementation. The syncenv thread is donated to qemu and ensures a single top-level coroutine is processed at a time. Qemu now has complete control over coroutine scheduling. BUG: 986775 Change-Id: I38223479a608d80353128e390f243933fc946fd6 Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-on: http://review.gluster.org/6110 Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Anand Avati <avati@redhat.com> 
The current coroutine model, mapping synctasks 1-1 with qemu internal
Coroutines, has some unresolved raciness issues. This problem usually
manifests as lifecycle mismatches between top-level (gluster created)
synctasks and the subsequently created internal coroutines from that
context. Qemu's internal queueing (and locking) can cause situations
where the top-level synctask is destroyed before the internal scheduler
has released references to memory, leading to use after free crashes
and asserts.

Simplify the coroutine model to use a single synctask as a coroutine
processor and rely on the existing native ucontext coroutine
implementation. The syncenv thread is donated to qemu and ensures a
single top-level coroutine is processed at a time. Qemu now has
complete control over coroutine scheduling.

BUG: 986775
Change-Id: I38223479a608d80353128e390f243933fc946fd6
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-on: http://review.gluster.org/6110
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>