Project Candle bug triage (25th October 2015)

[Nicholas Nethercote]

Greetings,

This is Project Candle bug triage email. The process used is described at
https://wiki.mozilla.org/Performance/Project_Candle#Bug_triage_process.

At the time of writing there are 11 unprioritized Power bugs, viewable at
http://mzl.la/1LVLJgD. In this thread I am discussing 8 of them.


* https://bugzilla.mozilla.org/show_bug.cgi?id=508427
* Firefox process chews through CPU even when in the background (or save my
laptop battery)

This one of those bugs with a vague title that has been open for years and had
many people pile onto it. Much of the discussion has been related to Linux,
which is something.

I suggest P3, and I will make the title more specific in an attempt to prevent
piling on.


* https://bugzilla.mozilla.org/show_bug.cgi?id=970927
* High power consumption on Forbes while idling, with CSS transition on
'transform' for an element inside of a "top: 3000px" subtree

I measured on Mac and we're only slightly worse than the competition. I suggest
P3.


* https://bugzilla.mozilla.org/show_bug.cgi?id=972392
* Canvas 2D has high power consumption on Linux

I suggest P3 because it's Linux.


* https://bugzilla.mozilla.org/show_bug.cgi?id=973881
* Cache I/O thread periodically writes to disk during idle
and
* https://bugzilla.mozilla.org/show_bug.cgi?id=973888
* mozStorage threads periodically write to disk during idle

Two similar bugs. These kinds of slow-burn bugs feel less important to me than
the ones where we are using heaps of power on a single site, though others may
disagree. I suggest P2.


* https://bugzilla.mozilla.org/show_bug.cgi?id=1052030
* high (100%) cpu use by plugin-container (no flash)

Another annoying one with vague symptoms. I suggest P3, and again I'll make the
title more specific.


* https://bugzilla.mozilla.org/show_bug.cgi?id=1131937
* Dramatically high CPU usage on facebook group page

Sounds bad (Facebook), but I don't have a good sense of how important the group
page is. P1? P2?


* https://bugzilla.mozilla.org/show_bug.cgi?id=1216148
* Geolocation does not turn off with browser backgrounded

Seems worth fixing, but probably not worthy of a P1. I suggest P2.

[Jonathan Hylands]

On Sun, Oct 25, 2015 at 8:28 PM, Nicholas Nethercote <n.neth...@gmail.com> wrote:

Greetings,

* https://bugzilla.mozilla.org/show_bug.cgi?id=1216148
* Geolocation does not turn off with browser backgrounded

Seems worth fixing, but probably not worthy of a P1. I suggest P2.

I'd like to discuss this a bit more - I think it is worthy of a P1. This is something people do often with their phones (at least, I do), and having it consume 62 mA when it is supposed to be consuming 1.2 mA once they put their phone back in their pocket is pretty nasty.

- Jon

[Richard Newman]

Two similar bugs. These kinds of slow-burn bugs feel less important to me than
the ones where we are using heaps of power on a single site, though others may
disagree. I suggest P2.

P2 sounds fine.

I'm interested to know to what extent these affect Android — I see no reason why they wouldn't — and thus if we might have found contributors to the frequent "Firefox eats my battery if it's left open in the background" bugs we get. If we're writing at all while the Gecko thread is live but the app is backgrounded, then at the very least we'll be nibbling at the battery with a guilty look on our faces.

 

* https://bugzilla.mozilla.org/show_bug.cgi?id=1216148
* Geolocation does not turn off with browser backgrounded

Seems worth fixing, but probably not worthy of a P1. I suggest P2.

Again, I'd like to know if this affects Android (and again, I see no reason why it wouldn't).

If so, I think it's a P1, simply because of the relative number of users. 

[Thomas Daede]

On 10/26/2015 05:19 AM, Jonathan Hylands wrote:

> I'd like to discuss this a bit more - I think it is worthy of a P1. This
> is something people do often with their phones (at least, I do), and
> having it consume 62 mA when it is supposed to be consuming 1.2 mA once
> they put their phone back in their pocket is pretty nasty.
>
> - Jon

As a foxfooder, I agree, accidentally opening Google Maps or anything
else that grabs location now means that GPS is on until your battery
dies. Trying to find and closing the GPS-using tab is a usability
disaster. I'll put more info on the bug.

[Nicholas Nethercote]

Thank you to all those who participated in this triage thread.

On Sun, Oct 25, 2015 at 5:28 PM, Nicholas Nethercote
<n.neth...@gmail.com> wrote:
>
> * https://bugzilla.mozilla.org/show_bug.cgi?id=508427
> * Firefox process chews through CPU even when in the background (or save my
> laptop battery)
>
> This one of those bugs with a vague title that has been open for years and had
> many people pile onto it. Much of the discussion has been related to Linux,
> which is something.
>
> I suggest P3, and I will make the title more specific in an attempt to prevent
> piling on.

I did P3 and renamed it.

> * https://bugzilla.mozilla.org/show_bug.cgi?id=970927
> * High power consumption on Forbes while idling, with CSS transition on
> 'transform' for an element inside of a "top: 3000px" subtree
>
> I measured on Mac and we're only slightly worse than the competition. I suggest
> P3.

I did P3.

> * https://bugzilla.mozilla.org/show_bug.cgi?id=972392
> * Canvas 2D has high power consumption on Linux
>
> I suggest P3 because it's Linux.

I did P3.

> * https://bugzilla.mozilla.org/show_bug.cgi?id=973881
> * Cache I/O thread periodically writes to disk during idle
> and
> * https://bugzilla.mozilla.org/show_bug.cgi?id=973888
> * mozStorage threads periodically write to disk during idle
>

> Two similar bugs. These kinds of slow-burn bugs feel less important to me than
> the ones where we are using heaps of power on a single site, though others may
> disagree. I suggest P2.

I did P2 for both, with agreement from rnewman.

> * https://bugzilla.mozilla.org/show_bug.cgi?id=1052030
> * high (100%) cpu use by plugin-container (no flash)
>
> Another annoying one with vague symptoms. I suggest P3, and again I'll make the
> title more specific.

I did P3 and renamed the bug.

> * https://bugzilla.mozilla.org/show_bug.cgi?id=1131937
> * Dramatically high CPU usage on facebook group page
>
> Sounds bad (Facebook), but I don't have a good sense of how important the group
> page is. P1? P2?

I did P1.

> * https://bugzilla.mozilla.org/show_bug.cgi?id=1216148
> * Geolocation does not turn off with browser backgrounded
>
> Seems worth fixing, but probably not worthy of a P1. I suggest P2.

I did P1 on the advice of jhylands, rnewman and tdaede.

Nick