Re: [Qemu-devel] -rtc clock=vm with -icount 1, sleep=off introduces unexpected delays in device interactions

[Nutaro, James J.]

My original problem seems to stem from something that changed in the way that 
device emulation and instruction execution interact (I'm guessing). To 
reproduce the issue, I started a linux image with

qemu-system-i386 -rtc clock=vm -monitor none -icount 1,sleep=off jack.img

After booting, I run

ping localhost

The first round trip time reports look reasonable, being in the millisecond to 
sub-millisecond range. These occur while the emulator is running slower than 
real time. 

After a bit, the emulator speeds up (skipping over idle periods during I/O?) 
and the round trip times jump to hundreds of milliseconds, which I had not 
expected.

If you want to try this experiment yourself, you can get the disk image that I 
used from here:

http://www.ornl.gov/~1qn/qemu-images/jack.img


Jim