On Wed, Nov 12, 2008 at 9:42 AM, Gleb Natapov <gleb@redhat.com> 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.