[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RFC PATCH v4 17/25] cpus: make icount warp determinist
From: |
Pavel Dovgaluk |
Subject: |
Re: [Qemu-devel] [RFC PATCH v4 17/25] cpus: make icount warp deterministic in replay mode |
Date: |
Fri, 7 Nov 2014 14:45:32 +0300 |
> From: Paolo Bonzini [mailto:address@hidden
> On 07/11/2014 11:33, Pavel Dovgalyuk wrote:
> > This patch adds saving and replaying warping parameters in record and replay
> > modes. These parameters affect on virtual clock values and therefore should
> > be deterministic.
>
> Why are QEMU_CLOCK_REALTIME timers not recorded/replayed like
> QEMU_CLOCK_HOST is?
We cannot record all QEMU_CLOCK_REALTIME timers, because they are
simulator-related timers,
not the VM-related ones. If we'll record them then we'll have to replay
simulator
execution. And we want just to replay VM allowing different realtime events to
be
non-replayable (like screen refresh, monitor events handling, and so on).
Pavel Dovgalyuk
>
> > Signed-off-by: Pavel Dovgalyuk <address@hidden>
> > ---
> > cpus.c | 24 +++++++++++++++++-------
> > 1 files changed, 17 insertions(+), 7 deletions(-)
> >
> > diff --git a/cpus.c b/cpus.c
> > index b41baf6..dac222b 100644
> > --- a/cpus.c
> > +++ b/cpus.c
> > @@ -370,7 +370,9 @@ static void icount_warp_rt(void *opaque)
> >
> > seqlock_write_lock(&timers_state.vm_clock_seqlock);
> > if (runstate_is_running()) {
> > - int64_t clock = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
> > + int64_t clock = qemu_clock_get_ns(replay_mode == REPLAY_MODE_NONE
> > + ? QEMU_CLOCK_REALTIME
> > + : QEMU_CLOCK_HOST);
> > int64_t warp_delta;
> >
> > warp_delta = clock - vm_clock_warp_start;
> > @@ -444,7 +446,9 @@ void qemu_clock_warp(QEMUClockType type)
> > }
> >
> > /* We want to use the earliest deadline from ALL vm_clocks */
> > - clock = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
> > + clock = qemu_clock_get_ns(replay_mode == REPLAY_MODE_NONE
> > + ? QEMU_CLOCK_REALTIME
> > + : QEMU_CLOCK_HOST);
> > deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL);
> > if (deadline < 0) {
> > return;
> > @@ -537,8 +541,10 @@ void configure_icount(QemuOpts *opts, Error **errp)
> > return;
> > }
> > icount_align_option = qemu_opt_get_bool(opts, "align", false);
> > - icount_warp_timer = timer_new_ns(QEMU_CLOCK_REALTIME,
> > - icount_warp_rt, NULL);
> > + icount_warp_timer = timer_new_ns(replay_mode == REPLAY_MODE_NONE
> > + ? QEMU_CLOCK_REALTIME
> > + : QEMU_CLOCK_HOST,
> > + icount_warp_rt, NULL);
> > if (strcmp(option, "auto") != 0) {
> > errno = 0;
> > icount_time_shift = strtol(option, &rem_str, 0);
> > @@ -562,10 +568,14 @@ void configure_icount(QemuOpts *opts, Error **errp)
> > the virtual time trigger catches emulated time passing too fast.
> > Realtime triggers occur even when idle, so use them less frequently
> > than VM triggers. */
> > - icount_rt_timer = timer_new_ms(QEMU_CLOCK_REALTIME,
> > - icount_adjust_rt, NULL);
> > + icount_rt_timer = timer_new_ms(replay_mode == REPLAY_MODE_NONE
> > + ? QEMU_CLOCK_REALTIME
> > + : QEMU_CLOCK_HOST,
> > + icount_adjust_rt, NULL);
> > timer_mod(icount_rt_timer,
> > - qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + 1000);
> > + qemu_clock_get_ms(replay_mode == REPLAY_MODE_NONE
> > + ? QEMU_CLOCK_REALTIME
> > + : QEMU_CLOCK_HOST) + 1000);
> > icount_vm_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
> > icount_adjust_vm, NULL);
> > timer_mod(icount_vm_timer,
> >
- Re: [Qemu-devel] [RFC PATCH v4 11/25] cpu-exec: allow temporary disabling icount, (continued)
- [Qemu-devel] [RFC PATCH v4 12/25] replay: interrupts and exceptions, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 13/25] replay: asynchronous events infrastructure, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 14/25] cpu: replay instructions sequence, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 15/25] replay: recording and replaying clock ticks, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 17/25] cpus: make icount warp deterministic in replay mode, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 16/25] replay: recording and replaying different timers, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 18/25] replay: shutdown event, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 19/25] replay: checkpoints, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 20/25] replay: bottom halves, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 21/25] replay: replay aio requests, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 22/25] replay: thread pool, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 23/25] replay: initialization and deinitialization, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 24/25] replay: command line options, Pavel Dovgalyuk, 2014/11/07
- [Qemu-devel] [RFC PATCH v4 25/25] replay: recording of the user input, Pavel Dovgalyuk, 2014/11/07