replay: don't process events at virtual clock checkpoint

As QEMU becomes more multi-threaded and non-synchronized, checkpoints
move from thread to thread. And the event queue that processed at checkpoints
should belong to the same thread in both record and replay executions.
This patch disables asynchronous event processing at virtual clock
checkpoint, because it may be invoked in different threads at record and
replay. This patch is temporary fix until the checkpoints are completely
refactored.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Message-Id: <20181018063345.7433.11678.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Pavel Dovgalyuk 2018-10-18 09:33:45 +03:00 committed by Paolo Bonzini
parent a8de011500
commit ca9759c2a9
2 changed files with 9 additions and 1 deletions

View File

@ -190,6 +190,7 @@ void replay_save_events(int checkpoint)
{ {
g_assert(replay_mutex_locked()); g_assert(replay_mutex_locked());
g_assert(checkpoint != CHECKPOINT_CLOCK_WARP_START); g_assert(checkpoint != CHECKPOINT_CLOCK_WARP_START);
g_assert(checkpoint != CHECKPOINT_CLOCK_VIRTUAL);
while (!QTAILQ_EMPTY(&events_list)) { while (!QTAILQ_EMPTY(&events_list)) {
Event *event = QTAILQ_FIRST(&events_list); Event *event = QTAILQ_FIRST(&events_list);
replay_save_event(event, checkpoint); replay_save_event(event, checkpoint);

View File

@ -214,7 +214,14 @@ bool replay_checkpoint(ReplayCheckpoint checkpoint)
/* This checkpoint belongs to several threads. /* This checkpoint belongs to several threads.
Processing events from different threads is Processing events from different threads is
non-deterministic */ non-deterministic */
if (checkpoint != CHECKPOINT_CLOCK_WARP_START) { if (checkpoint != CHECKPOINT_CLOCK_WARP_START
/* FIXME: this is temporary fix, other checkpoints
may also be invoked from the different threads someday.
Asynchronous event processing should be refactored
to create additional replay event kind which is
nailed to the one of the threads and which processes
the event queue. */
&& checkpoint != CHECKPOINT_CLOCK_VIRTUAL) {
replay_save_events(checkpoint); replay_save_events(checkpoint);
} }
res = true; res = true;