[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy lo
From: |
Glauber Costa |
Subject: |
Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load. |
Date: |
Wed, 12 Nov 2008 09:54:09 -0200 |
On Wed, Nov 12, 2008 at 9:42 AM, Gleb Natapov <address@hidden> wrote:
> On Tue, Nov 11, 2008 at 02:17:49PM -0600, Anthony Liguori wrote:
>> Gleb Natapov wrote:
>>> On Mon, Nov 10, 2008 at 09:46:12AM -0600, Anthony Liguori wrote:
>>> -usbdevice tablet has nothing to do with it. Qemu misses interrupt
>>> even
>>> without this option and with SDL screen it misses them in bunches when
>>> SDL redraws a screen. In case of vnc qemu misses interrupt because of
>>> fsync() call in raw_flush(), or so my instrumentation shows.
>>>
>>
>> Can you give this patch a spin?
>>
> Doesn't compile for me. fd_pool_inuse and fd_inuse are used but not
> defined.
>
>> This introduces a bdrv_aio_flush() which will wait for all existing AIO
>> operations to complete before indicating completion. It also fixes up
>> IDE. Fixing up SCSI will be a little more tricky but not much. Since
>> we now use O_DSYNC, it's unnecessary to do an fsync (or an fdatasync).
>>
>> Assuming you're using IDE, this should eliminate any delays from fsync.
> I am using IDE.
>
>> SDL delays are unavoidable because it's going to come down to SDL doing
>> sychronous updates to the X server. The proper long term solution here
>> would be to put SDL in it's own thread but I'm not too worried about
> And probably time-keeping deserves its own thread. And CPU execution
> too.
It might well be a stupid idea, (would have to benchmark it), but the
other day it occurred to me
that we could keep timekeeping in a separate _process_, with a shm
area, doing timekeeping
for all running guests.
--
Glauber Costa.
"Free as in Freedom"
http://glommer.net
"The less confident you are, the more serious you have to act."
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., (continued)
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Anthony Liguori, 2008/11/09
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Gleb Natapov, 2008/11/10
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Anthony Liguori, 2008/11/10
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Gleb Natapov, 2008/11/10
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Anthony Liguori, 2008/11/10
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Gleb Natapov, 2008/11/10
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Gleb Natapov, 2008/11/11
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Anthony Liguori, 2008/11/11
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Anthony Liguori, 2008/11/11
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Gleb Natapov, 2008/11/12
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load.,
Glauber Costa <=
- Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Dor Laor, 2008/11/12
Re: [Qemu-devel] [RESEND][PATCH 0/3] Fix guest time drift under heavy load., Jamie Lokier, 2008/11/05