1501126 - [Mac] Enable sandbox early startup by default on Nightly

Status: RESOLVED FIXED

(Core :: Security: Process Sandboxing, enhancement, P1)

Description

[Haik Aftandilian [:haik]]

Enable the early startup mode of the Mac content sandbox by default in Nightly by default (by setting security.sandbox.content.mac.earlyinit=true).

Comment 1

[Haik Aftandilian [:haik]]

From bug 1431441 comment 33 by Ionut
> Before the backout, we noticed these big performance regressions:
> 
> == Change summary for alert #16766 (as of Fri, 12 Oct 2018 13:23:55 GMT) ==
> 
> Regressions:
> 
> 16%  sessionrestore osx-10-10 opt e10s stylo                     640.67 -> 745.17
> 13%  ts_paint osx-10-10 opt e10s stylo                           707.67 -> 802.83
> 13%  sessionrestore_no_auto_restore osx-10-10 opt e10s stylo     675.29 -> 764.67
> 13%  ts_paint_webext osx-10-10 opt e10s stylo                    712.33 -> 803.92
> 
> For up to date results, see: https://treeherder.mozilla.org/perf.html#/alerts?id=16766

The changes move our call to sandbox_init_with_parameters() in content processes from being run on the main thread event loop during initialization to early in main.

I do not think the regressions in sessionrestore, ts_paint, or ts_paint_webext are meaningful because it appears that those tests previously (without the code changes) didn't include the execution time of sandbox_init_with_parameters(), but do now that the function has been moved. I tested this by adding a 0.5 second busy loop in the original code site and found that it didn't affect those benchmarks.

That wasn't the case for sessionrestore_no_auto_restore.

I need some help understanding exactly what these tests are timing though. Ionut, are you able to help with that or is there someone you can recommend?

I also found that sandbox_init_with_parameters() is much slower on older hardware like we have on try. Some rough numbers I collected for the average execution time:

2008 MacBook with macOS 10.9:                         500ms
try hardware (t-yosemite-r7-186) with macOS 10.10:    122ms
2015 MacBook Air with macOS 10.14:                     15ms
2012 MacBook Pro with macOS 10.11:                     14ms
2018 MacBook Pro with macOS 10.14:                      8ms

Comment 2

[Haik Aftandilian [:haik]]

@Ionut, jmaher offered to help with my questions. Is it OK to land while still resolving this?

Comment 3

[Ionuț Goldan [:igoldan]]

(In reply to Haik Aftandilian [:haik] from comment #1)
> From bug 1431441 comment 33 by Ionut
> > Before the backout, we noticed these big performance regressions:
> > 
> > == Change summary for alert #16766 (as of Fri, 12 Oct 2018 13:23:55 GMT) ==
> > 
> > Regressions:
> > 
> > 16%  sessionrestore osx-10-10 opt e10s stylo                     640.67 -> 745.17
> > 13%  ts_paint osx-10-10 opt e10s stylo                           707.67 -> 802.83
> > 13%  sessionrestore_no_auto_restore osx-10-10 opt e10s stylo     675.29 -> 764.67
> > 13%  ts_paint_webext osx-10-10 opt e10s stylo                    712.33 -> 803.92
> > 
> > For up to date results, see: https://treeherder.mozilla.org/perf.html#/alerts?id=16766
>
> I need some help understanding exactly what these tests are timing though.
> Ionut, are you able to help with that or is there someone you can recommend?

Yes, for sessionrestore* test you can contact :mikedeboer.
As for ts_paint, it used to be :milan, but now I think one of the contacts would be :davidb.

Comment 4

[Ionuț Goldan [:igoldan]]

(In reply to Haik Aftandilian [:haik] from comment #2)
> @Ionut, jmaher offered to help with my questions. Is it OK to land while
> still resolving this?

You can land this, it's just that I need constant feedback on the evolution of the fix, from your behalf.

Comment 5

[Haik Aftandilian [:haik]]

I think bug 1505445 will address the talos regressions listed in comment 3. I plan to land this fix after bug 1505445 which is out for review.

Comment 6

[Haik Aftandilian [:haik]]

Attachment: Bug 1501126 - [Mac] Enable sandbox early startup by default on Nightly r?Alex_Gaynor

Set security.sandbox.content.mac.earlyinit=true to enable sandbox early startup by default on Nightly only.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/22d335fc020f
[Mac] Enable sandbox early startup by default on Nightly r=Alex_Gaynor

Comment 8

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/22d335fc020f