From ca9759c2a92f528f256fef0e3922416f7bb47bf9 Mon Sep 17 00:00:00 2001
From: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Date: Thu, 18 Oct 2018 09:33:45 +0300
Subject: [PATCH] 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>
---
replay/replay-events.c | 1 +
replay/replay.c | 9 ++++++++-
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/replay/replay-events.c b/replay/replay-events.c
index 0964a82838..d9a2d495b9 100644
--- a/replay/replay-events.c
+++ b/replay/replay-events.c
@@ -190,6 +190,7 @@ void replay_save_events(int checkpoint)
{
g_assert(replay_mutex_locked());
g_assert(checkpoint != CHECKPOINT_CLOCK_WARP_START);
+ g_assert(checkpoint != CHECKPOINT_CLOCK_VIRTUAL);
while (!QTAILQ_EMPTY(&events_list)) {
Event *event = QTAILQ_FIRST(&events_list);
replay_save_event(event, checkpoint);
diff --git a/replay/replay.c b/replay/replay.c
index 379b51ab46..8b172b2d1b 100644
--- a/replay/replay.c
+++ b/replay/replay.c
@@ -214,7 +214,14 @@ bool replay_checkpoint(ReplayCheckpoint checkpoint)
/* This checkpoint belongs to several threads.
Processing events from different threads is
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);
}
res = true;