Re: Prezeroing V2 [0/3]: Why and When it works

From: David S. Miller
Date: Mon Dec 27 2004 - 17:56:12 EST


On Fri, 24 Dec 2004 10:21:24 -0800 (PST)
Linus Torvalds <torvalds@xxxxxxxx> wrote:

> Absolutely. I would want to see some real benchmarks before we do this.
> Not just some microbenchmark of "how many page faults can we take without
> _using_ the page at all".

Here's my small contribution. I did three "make -j3 vmlinux" timed
runs, one running a kernel without the pre-zeroing stuff applied,
one with it applied. It did shave a few seconds off the build
consistently. Here is the before:

real 8m35.248s
user 15m54.132s
sys 1m1.098s

real 8m32.202s
user 15m54.329s
sys 1m0.229s

real 8m31.932s
user 15m54.160s
sys 1m0.245s

and here is the after:

real 8m29.375s
user 15m43.296s
sys 0m59.549s

real 8m28.213s
user 15m39.819s
sys 0m58.790s

real 8m26.140s
user 15m44.145s
sys 0m58.872s
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