Re: [PATCH 2.6.11-rc4-mm1] connector: Add a fork connector

From: Guillaume Thouvenin
Date: Tue Mar 08 2005 - 03:47:32 EST

On Tue, 2005-03-08 at 08:29 +0100, Guillaume Thouvenin wrote:
> - Run the lmbench with the user space application that manages
> group of processus. if fork connector is not used the only
> overhead is a test in the do_fork() routine.

For information here are some results when using the process creation
tests "lat_proc fork". Test was run ten times thus the average is
computed with the ten metrics.

with a kernel 2.6.11-rc4-mm1
max value = 164.0588 msec
min value = 159.8571 msec
average = 161.7012 msec

with a kernel 2.6.11-rc4-mm1 and the cnfork (cn_fork_enable == 0)
max value = 163.3438 msec
min value = 159.8857 msec
average = 160.9447 msec

with a kernel 2.6.11-rc4-mm1 and the cnfork (cn_fork_enable == 1)
max value = 177.6885 msec
min value = 170.9057 msec
average = 173.7675 msec

So we see that when the fork connector is disable the time it takes to
split a process into two copies is the same (and it's normal) and when
the fork connector is enable, it's around 7.5% slower.


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