608956 - Enabling methodjit in chrome regresses Ts and Tshutdown

Status: RESOLVED INVALID

(Core :: JavaScript Engine, defect)

Description

[Mark Finkle (:mfinkle) (use needinfo?)]

Are there things we can do to reduce the effects of methodjit on startup and shutdown?

Comment 1

[Mark Finkle (:mfinkle) (use needinfo?)]

Regression Ts increase 3.53% on Nokia n900 mobile
----------------------------------------------------
    Previous: avg 6990.074 stddev 105.673 of 30 runs up to revision aa1334b58f2f
    New     : avg 7237.112 stddev 9.717 of 5 runs since revision e67c727487a8
    Change  : +247.038 (3.53% / z=2.338)
    Graph   : http://mzl.la/a4FO7D

Changeset range: http://hg.mozilla.org/mobile-browser/pushloghtml?fromchange=aa1334b58f2f&tochange=e67c727487a8


Regression Ts Shutdown increase 95.5% on Nokia n900 mobile
-------------------------------------------------------------
    Previous: avg 1474.241 stddev 40.252 of 30 runs up to revision aa1334b58f2f
    New     : avg 2882.334 stddev 87.119 of 5 runs since revision e67c727487a8
    Change  : +1408.093 (95.5% / z=34.982)
    Graph   : http://mzl.la/bxh004

Changeset range: http://hg.mozilla.org/mobile-browser/pushloghtml?fromchange=aa1334b58f2f&tochange=e67c727487a8

Comment 2

[Mike Shaver (:shaver emeritus)]

Where is the time being spent?  Doubling the shutdown time should show up like a supernova on a profile of it.

Comment 3

[Mark Finkle (:mfinkle) (use needinfo?)]

I had some oprofile logs from startup. Will attach

Comment 4

[Mark Finkle (:mfinkle) (use needinfo?)]

Attachment: startup report

Comment 5

[Mark Finkle (:mfinkle) (use needinfo?)]

Attachment: startup callgraph

Comment 6

[Mark Finkle (:mfinkle) (use needinfo?)]

Attachment: shutdown report

Comment 7

[Mark Finkle (:mfinkle) (use needinfo?)]

Attachment: shutdown callgraph

Comment 8

[Oleg Romashin (:romaxa)]

Do you have callgraph without mjit enabled? just to compare it correctly... or how did you get this profile?

Comment 9

[Mark Finkle (:mfinkle) (use needinfo?)]

(In reply to comment #8)
> Do you have callgraph without mjit enabled?

Not at the moment. I could probably make some

> just to compare it correctly... or
> how did you get this profile?

These profiles are with methodjit enabled

Comment 10

[Oleg Romashin (:romaxa)]

Can we make some build request and measure Ts with mjit enabled/disabled again?

Comment 11

[Mark Finkle (:mfinkle) (use needinfo?)]

chrome mjit did not regress startup the next time we enabled it, but we disabled it again for memory reasons.