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Re: [Qemu-devel] [PATCH v3] Optimize record/replay checkpointing for all
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH v3] Optimize record/replay checkpointing for all clocks it applies to |
Date: |
Thu, 18 Oct 2018 14:17:31 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.0 |
On 18/10/2018 13:16, Artem Pisarenko wrote:
> Removes redundant checkpoints in replay log when there are no expired timers
> in timers list, associated with corresponding clock (i.e. no rr events
> associated with current clock value).
> This also improves performance in rr mode.
>
> Signed-off-by: Artem Pisarenko <address@hidden>
> ---
>
> Oops, forgot to commit this fix
>
> v3:
> - fixed compiler warning caused non-debug build to fail
We can also move the switch statement to a separate function, it
simplifies the code:
diff --git a/util/qemu-timer.c b/util/qemu-timer.c
index 8a2ad3bce2..3a64ce33d3 100644
--- a/util/qemu-timer.c
+++ b/util/qemu-timer.c
@@ -482,6 +482,26 @@ bool timer_expired(QEMUTimer *timer_head, int64_t
current_time)
return timer_expired_ns(timer_head, current_time * timer_head->scale);
}
+static bool timer_checkpoint(QEMUClockType clock)
+{
+ if (replay_mode != REPLAY_MODE_NONE) {
+ switch (clock) {
+ case QEMU_CLOCK_VIRTUAL:
+ return replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL);
+ case QEMU_CLOCK_HOST:
+ return replay_checkpoint(CHECKPOINT_CLOCK_HOST);
+ case QEMU_CLOCK_VIRTUAL_RT:
+ return replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL_RT);
+ default:
+ /* QEMU_CLOCK_REALTIME is external to the emulation and does
+ * not need checkpointing.
+ */
+ break;
+ }
+ }
+ return true;
+}
+
bool timerlist_run_timers(QEMUTimerList *timer_list)
{
QEMUTimer *ts;
@@ -489,8 +509,7 @@ bool timerlist_run_timers(QEMUTimerList *timer_list)
bool progress = false;
QEMUTimerCB *cb;
void *opaque;
- bool need_replay_checkpoint = false;
- ReplayCheckpoint replay_checkpoint_id;
+ bool need_replay_checkpoint = true;
if (!atomic_read(&timer_list->active_timers)) {
return false;
@@ -501,28 +520,6 @@ bool timerlist_run_timers(QEMUTimerList *timer_list)
goto out;
}
- if (replay_mode != REPLAY_MODE_NONE) {
- /* Postpone actual checkpointing to timer list processing
- * to properly check if we actually need it.
- */
- switch (timer_list->clock->type) {
- case QEMU_CLOCK_VIRTUAL:
- need_replay_checkpoint = true;
- replay_checkpoint_id = CHECKPOINT_CLOCK_VIRTUAL;
- break;
- case QEMU_CLOCK_HOST:
- need_replay_checkpoint = true;
- replay_checkpoint_id = CHECKPOINT_CLOCK_HOST;
- break;
- case QEMU_CLOCK_VIRTUAL_RT:
- need_replay_checkpoint = true;
- replay_checkpoint_id = CHECKPOINT_CLOCK_VIRTUAL_RT;
- break;
- default:
- break;
- }
- }
-
/*
* Extract expired timers from active timers list and and process them,
* taking into account checkpointing required in rr mode.
@@ -545,11 +542,11 @@ bool timerlist_run_timers(QEMUTimerList *timer_list)
break;
}
if (need_replay_checkpoint
&& !(ts->attributes & QEMU_TIMER_ATTR_EXTERNAL)) {
/* once we got here, checkpoint clock only once */
need_replay_checkpoint = false;
qemu_mutex_unlock(&timer_list->active_timers_lock);
- if (!replay_checkpoint(replay_checkpoint_id)) {
+ if (!timer_checkpoint(timer_list->clock->type)) {
goto out;
}
qemu_mutex_lock(&timer_list->active_timers_lock);
No need to do anything on your part.
Paolo
- [Qemu-devel] [PATCH v3 0/4] Introduce attributes for timers subsystem and remove QEMU_CLOCK_VIRTUAL_EXT clock type, Artem Pisarenko, 2018/10/18
- [Qemu-devel] [PATCH v3 4/4] Optimize record/replay checkpointing for all clocks it applies to, Artem Pisarenko, 2018/10/18
- [Qemu-devel] [PATCH v3 1/4] Revert some patches from recent [PATCH v6] "Fixing record/replay and adding reverse debugging", Artem Pisarenko, 2018/10/18
- [Qemu-devel] [PATCH v3 3/4] Restores record/replay behavior related to special virtual clock processing for timers used in external subsystems., Artem Pisarenko, 2018/10/18
- [Qemu-devel] [PATCH v3 2/4] Introduce attributes to qemu timer subsystem, Artem Pisarenko, 2018/10/18
- [Qemu-devel] [PATCH v3] Optimize record/replay checkpointing for all clocks it applies to, Artem Pisarenko, 2018/10/18
- Re: [Qemu-devel] [PATCH v3] Optimize record/replay checkpointing for all clocks it applies to,
Paolo Bonzini <=
- Re: [Qemu-devel] [PATCH v3] Optimize record/replay checkpointing for all clocks it applies to, Artem Pisarenko, 2018/10/18
- Re: [Qemu-devel] [PATCH v3] Optimize record/replay checkpointing for all clocks it applies to, Paolo Bonzini, 2018/10/18
- Re: [Qemu-devel] [PATCH v3] Optimize record/replay checkpointing for all clocks it applies to, Artem Pisarenko, 2018/10/18
- Re: [Qemu-devel] [PATCH v3] Optimize record/replay checkpointing for all clocks it applies to, Paolo Bonzini, 2018/10/18
- Re: [Qemu-devel] [PATCH v3] Optimize record/replay checkpointing for all clocks it applies to, Artem Pisarenko, 2018/10/18
Re: [Qemu-devel] [PATCH v3 0/4] Introduce attributes for timers subsystem and remove QEMU_CLOCK_VIRTUAL_EXT clock type, Artem Pisarenko, 2018/10/18
[Qemu-devel] [PATCH v3 4/4] Optimize record/replay checkpointing for all clocks it applies to, Artem Pisarenko, 2018/10/18