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[Qemu-devel] [RFC PATCH v3 23/30] replay: avoid recursive call of checkp
From: |
Pavel Dovgalyuk |
Subject: |
[Qemu-devel] [RFC PATCH v3 23/30] replay: avoid recursive call of checkpoints |
Date: |
Thu, 11 Jan 2018 11:27:05 +0300 |
User-agent: |
StGit/0.17.1-dirty |
This patch adds a flag which denies recursive call of replay_checkpoint
function. Checkpoints may be accompanied by the hardware events. When event
is processed, virtual device may invoke timer modification functions that
also invoke the checkpoint function. This leads to infinite loop.
Signed-off-by: Pavel Dovgalyuk <address@hidden>
---
replay/replay.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/replay/replay.c b/replay/replay.c
index 585c5de..c9fd984 100644
--- a/replay/replay.c
+++ b/replay/replay.c
@@ -176,13 +176,24 @@ void replay_shutdown_request(ShutdownCause cause)
bool replay_checkpoint(ReplayCheckpoint checkpoint)
{
bool res = false;
+ static bool in_checkpoint = false;
assert(EVENT_CHECKPOINT + checkpoint <= EVENT_CHECKPOINT_LAST);
- replay_save_instructions();
if (!replay_file) {
return true;
}
+ if (in_checkpoint) {
+ /* If we are already in checkpoint, then there is no need
+ for additional synchronization.
+ Recursion occurs when HW event modifies timers.
+ Timer modification may invoke the checkpoint and
+ proceed to recursion. */
+ return true;
+ }
+ in_checkpoint = true;
+
+ replay_save_instructions();
if (replay_mode == REPLAY_MODE_PLAY) {
g_assert(replay_mutex_locked());
@@ -204,6 +215,7 @@ bool replay_checkpoint(ReplayCheckpoint checkpoint)
res = true;
}
out:
+ in_checkpoint = false;
return res;
}
- [Qemu-devel] [RFC PATCH v3 14/30] target/arm/arm-powertctl: drop BQL assertions, (continued)
- [Qemu-devel] [RFC PATCH v3 14/30] target/arm/arm-powertctl: drop BQL assertions, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 15/30] cpus: push BQL lock to qemu_*_wait_io_event, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 16/30] cpus: only take BQL for sleeping threads, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 17/30] replay/replay.c: bump REPLAY_VERSION again, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 18/30] replay/replay-internal.c: track holding of replay_lock, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 19/30] replay: make locking visible outside replay code, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 20/30] replay: push replay_mutex_lock up the call tree, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 21/30] replay: don't destroy mutex at exit, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 22/30] replay: check return values of fwrite, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 23/30] replay: avoid recursive call of checkpoints,
Pavel Dovgalyuk <=
- [Qemu-devel] [RFC PATCH v3 24/30] scripts/qemu-gdb: add simple tcg lock status helper, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 25/30] util/qemu-thread-*: add qemu_lock, locked and unlock trace events, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 26/30] scripts/analyse-locks-simpletrace.py: script to analyse lock times, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 27/30] scripts/replay-dump.py: replay log dumper, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 28/30] scripts/qemu-gdb/timers.py: new helper to dump timer state, Pavel Dovgalyuk, 2018/01/11
- [Qemu-devel] [RFC PATCH v3 29/30] replay: improve replay performance, Pavel Dovgalyuk, 2018/01/11