Make the morejs page cycler measure cold times better.

Make the morejs page cycler measure cold times better.

Currently it only does one cold run per page, so the results are noisy.

BUG=350858
R=dtu@chromium.org, fmeawad@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=256595

[marja, 2014-03-12 12:59:29]

fmeawad, ptal.

[fmeawad, 2014-03-12 17:18:25]

LGTM, you will also need an owner.

[marja, 2014-03-12 17:28:12]

I'm an owner :) But it would be good for tonyg@ to ACK this, since I might not
be up to date wrt can this kind of change break something.

tonyg, ptal

[dtu, 2014-03-12 18:13:40]

lgtm, no weird side effects here :)

[marja, 2014-03-12 19:17:44]

Committed patchset #1 manually as r256595 (presubmit successful).

[tonyg, 2014-03-14 01:50:55]

Oops, I was too slow, sorry.

What I'd actually like to do is to change the default cold-load-percent to 50
for all page cyclers and leave the iterations at 10. Would that work for you?

[marja, 2014-03-14 11:04:46]

On 2014/03/14 01:50:55, tonyg wrote:
> Oops, I was too slow, sorry.
> 
> What I'd actually like to do is to change the default cold-load-percent to 50
> for all page cyclers and leave the iterations at 10. Would that work for you?

In general yes, if the data we get from 5 runs is stable enough. I haven't
looked if the page cycler noise currently has is like "different runs take very
different times" or "all runs take generally the same, just for some reason
running the page set *now* versus 10 min ago takes different time". If it's the
latter kind of noise, dropping the runs to 5 should work.