Re: AIM7 40% regression with 2.6.26-rc1

From: Ingo Molnar
Date: Thu May 08 2008 - 03:39:53 EST



* Zhang, Yanmin <yanmin_zhang@xxxxxxxxxxxxxxx> wrote:

> > great! Yanmin, could you please also check the other patch i sent
> > (also attached below), does it solve the regression similarly?
>
> With your patch, aim7 regression becomes less than 2%. I ran the
> testing twice.
>
> Linus' patch could recover it completely. As aim7 result is quite
> stable(usually fluctuating less than 1%), 1.5%~2% is a little big.

is this the old original aim7 you are running, or osdl-aim-7 or
re-aim-7?

if it's aim7 then this is a workload that starts+stops 2000 parallel
tasks that each start and exit at the same time. That might explain its
sensitivity on the BKL - this is all about tty-controlled task startup
and exit.

i could not get it to produce anywhere close to stable results though. I
also frequently get into this problem:

AIM Multiuser Benchmark - Suite VII Run Beginning
Tasks jobs/min jti jobs/min/task real cpu
2000
Failed to execute
new_raph 200
Unable to solve equation in 100 tries. P = 1.5708, P0 = 1.5708, delta = 6.12574e-17

Failed to execute
disk_cp /mnt/shm
disk_cp (1): cannot open /mnt/shm/tmpa.common
disk1.c: No such file or directory

[.. etc. a large stream of them .. ]

system has 2GB of RAM and tmpfs mounted to the place where aim7 puts its
work files.

Ingo
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