From: Avi Kivity <avi@redhat.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: qemu-devel <qemu-devel@nongnu.org>,
Glauber Costa <glommer@redhat.com>,
Ulrich Obergfell <uobergfe@redhat.com>, kvm <kvm@vger.kernel.org>
Subject: Re: [Qemu-devel] Re: [RFC: 0/2] patch for QEMU HPET periodic timer emulation to alleviate time drift
Date: Mon, 07 Feb 2011 17:08:44 +0200 [thread overview]
Message-ID: <4D500AFC.4040206@redhat.com> (raw)
In-Reply-To: <4D50094D.1040003@siemens.com>
On 02/07/2011 05:01 PM, Jan Kiszka wrote:
> >
> > On the other hand, we need a way to inject lost ticks into a
> > PeriodicTimer. If interrupt injection detects that an interrupt was
> > coalesced, we want the timer to schedule a new tick for us.
>
> Isn't absence of corresponding call to periodic_timer_ack() sufficient?
It probably is. However, that API is easy to misuse; if you forget to
call it, the timer goes crazy. The default behaviour should be to
assume an ack and the API should provide adjustments.
Also need to design the API carefully for changing frequency (Windows is
known to do that) and switching from periodic to single shot. For the
first case I guess we need to adjust the deferred ticks to the new time
base (so if the frequency doubles, the lost ticks up to that point
double as well). For the second case, I guess we just lose time.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-02-07 15:08 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <480481933.225059.1296734409954.JavaMail.root@zmail07.collab.prod.int.phx2.redhat.com>
[not found] ` <1375835067.226263.1296740625327.JavaMail.root@zmail07.collab.prod.int.phx2.redhat.com>
2011-02-03 15:28 ` [Qemu-devel] Re: [RFC: 0/2] patch for QEMU HPET periodic timer emulation to alleviate time drift Jan Kiszka
2011-02-03 20:07 ` Anthony Liguori
2011-02-03 21:24 ` Jan Kiszka
2011-02-04 2:06 ` Anthony Liguori
2011-02-04 8:56 ` Jan Kiszka
2011-02-07 12:34 ` Avi Kivity
2011-02-07 13:11 ` Anthony Liguori
2011-02-07 13:14 ` Avi Kivity
2011-02-07 13:23 ` Anthony Liguori
2011-02-07 13:34 ` Avi Kivity
2011-02-07 13:41 ` Gleb Natapov
2011-02-07 13:46 ` Avi Kivity
2011-02-07 13:48 ` Gleb Natapov
2011-02-07 13:51 ` Avi Kivity
2011-02-07 13:54 ` Gleb Natapov
2011-02-07 14:10 ` Jan Kiszka
2011-02-07 14:28 ` Anthony Liguori
2011-02-07 14:43 ` Jan Kiszka
2011-02-07 14:54 ` Anthony Liguori
2011-02-07 14:57 ` Jan Kiszka
2011-02-07 15:01 ` Anthony Liguori
2011-02-07 15:08 ` Jan Kiszka
2011-02-07 15:13 ` Avi Kivity
2011-02-07 15:17 ` Jan Kiszka
2011-02-07 15:29 ` Avi Kivity
2011-02-07 19:30 ` Anthony Liguori
2011-02-08 9:11 ` Avi Kivity
2011-02-07 15:20 ` Jan Kiszka
2011-02-07 15:30 ` Avi Kivity
2011-02-07 19:28 ` Anthony Liguori
2011-02-07 14:58 ` Avi Kivity
2011-02-07 15:01 ` Jan Kiszka
2011-02-07 15:08 ` Avi Kivity [this message]
2011-02-07 15:14 ` Jan Kiszka
2011-02-07 15:16 ` Avi Kivity
2011-02-07 15:22 ` Anthony Liguori
2011-02-07 15:18 ` Anthony Liguori
2011-02-04 9:52 ` Ulrich Obergfell
2011-02-07 10:44 ` Ulrich Obergfell
2011-02-07 13:24 ` Anthony Liguori
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