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Date: Fri, 04 Nov 2005 17:17:26 +0200
From: Andriy Gapon <avg@icyb.net.ua>
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Subject: kqemu speed up
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How much does kqemu speed up qemu ?
What is the typical difference in speed between guest running in
qemu+kqemu and host ?

The reason I am asking is the following:

host (FreeBSD 5.4):
$ /usr/bin/time -h dd if=/dev/random of=/dev/null bs=4 count=100k
102400+0 records in
102400+0 records out
409600 bytes transferred in 0.342956 secs (1194322 bytes/sec)
        0.34s real              0.03s user              0.25s sys

$ fstat /dev/kqemu0
USER     CMD          PID   FD MOUNT      INUM MODE         SZ|DV R/W NAME
root     qemu       18715    9 /dev        203 crw-rw----  kqemu0 rw
/dev/kqemu0


guest (FreeBSD 6.0):
$ /usr/bin/time -h dd if=/dev/random of=/dev/null bs=4 count=10k
10240+0 records in
10240+0 records out
409600 bytes transferred in 59.620314 secs (6870 bytes/sec)
        59.76s real             1.96s user              55.29s sys

As you can see the difference is two orders of magnitude. I think I had
similar figures without kqemu and I thought that with kqemu guest speed
is close to host speed. What gives ?

-- 
Andriy Gapon