1157638 - Write a script to easily detect applications that keep running when the phone is in standby and/or not connected via ADB

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Developer Tools, defect)

Description

[Gabriele Svelto [:gsvelto]]

The Flame has kernel tracing support fully enabled which allows us to easily track what applications are running even when the phone is not connected to a computer or even in standby mode. This would be useful to quickly diagnose battery-draining bugs that are often hard to debug as they happen when the phone is disconnected and in standby. Since kernel tracing is universally available this would also work on phones using user/production builds.

The script should enable tracing sched_stat_runtime events to know which applications have run and for how long and sched_wakeup events to know how many times the app woke up to run. The script should also process the trace when pulling it from the phone and create a readable summary out of it.

This is my contribution for April's hack-day, I've CC'ed everybody who was on the Etherpad + other people whom I think might be interested.

Comment 1

[Alexandre Poirot [:ochameau]]

And now you would like to display this data in devtools?
In on-device devtools (Developer hud), or once you connect the device to a computer (webide)?
Note that WebIDE has a "Monitor" feature, that is extensible and can call some local commands to pull useful data about apps/OS.

You are talking about a "script" is that a shell script running some adb shell commands?

Comment 2

[Thomas Zimmermann [:tzimmermann] [:tdz]]

Thanks, that sounds very interesting. Is it possible to include wake-lock statistics into the output?

Comment 3

[Gabriele Svelto [:gsvelto]]

Attachment: [PULL REQUEST] Add a script to easily trace applications

Comment 4

[Gabriele Svelto [:gsvelto]]

(In reply to Alexandre Poirot [:ochameau] from comment #1)
> And now you would like to display this data in devtools?

For now I settled for a simple shell script but integrating this into devtools would be mighty cool.

> Note that WebIDE has a "Monitor" feature, that is extensible and can call
> some local commands to pull useful data about apps/OS.

I think that would make using this data directly into WebIDE very easy.

> You are talking about a "script" is that a shell script running some adb
> shell commands?

Yes. Try the attached script:

$ trace.sh --start

(do stuff even with your phone disconnected)

$ trace.sh --stop
            NAME   PID WAKEUPS      RUNTIME NEW
             b2g   751       0      3957 ms  no
          (Nuwa)   764       0         2 ms  no
      Homescreen  1180       0       714 ms  no
 Built-in Keyboa  1193       0        17 ms  no
           Usage  1568       0        10 ms  no
        Settings  1575       0        24 ms  no
 Smart Collectio  1853       0         2 ms  no
  Communications  1873       0      2316 ms  no
  Find My Device  7976       0        26 ms  no
          Camera  8424       0         7 ms  no
        Messages  9016       0         8 ms  no
          E-Mail 14409       0      2821 ms  no

The script is still incomplete as it's a WIP so the WAKEUPS (how many times the app woke up) and NEW (was the app launched during tracing?) are not populated yet. Being a shell script it's also dog slow.

Comment 5

[Alexandre Poirot [:ochameau]]

See this page on how to integrate with the Monitor:
  https://developer.mozilla.org/en-US/docs/Tools/WebIDE/Monitor
For local commands it relies on connecting to a WebSocket server serving some JSON objects with the data.
I think there is some existing python command that does the websocket+adb thing somewhere if you are interested in this approach.
Doesn't sounds very easy from a bash script. But also see direct JS/C++ integration from code running directly within gecko.

Comment 6

[Gabriele Svelto [:gsvelto]]

(In reply to Alexandre Poirot [:ochameau] from comment #5)
> See this page on how to integrate with the Monitor:
>   https://developer.mozilla.org/en-US/docs/Tools/WebIDE/Monitor
> For local commands it relies on connecting to a WebSocket server serving
> some JSON objects with the data.
> I think there is some existing python command that does the websocket+adb
> thing somewhere if you are interested in this approach.
> Doesn't sounds very easy from a bash script. But also see direct JS/C++
> integration from code running directly within gecko.

Python will be fine for that, thanks for the pointer. I wrote a shell script so that we would be able to quickly use it immediately before I turn it into something more polished.

Comment 7

[Gabriele Svelto [:gsvelto]]

I've pushed an updated script which properly traces wakeups and process creation, this is the output of me launching "Saga of Craigen - Ambush at the Dragon Pass" (arguably the best game ever made for Firefox OS):

            NAME   PID WAKEUPS      RUNTIME NEW
             b2g   751     580      1300 ms  no
          (Nuwa)   764       0         0 ms  no
      Homescreen  1180      76       273 ms  no
 Built-in Keyboa  1193       0         0 ms  no
           Usage  1568      27        19 ms  no
        Settings  1575      30       127 ms  no
 Smart Collectio  1853      35        20 ms  no
  Communications  1873      48       467 ms  no
  Find My Device  7976      11        15 ms  no
          Camera  8424       2        16 ms  no
        Messages  9016      47       211 ms  no
          E-Mail 14409      23        42 ms  no
         Gallery 16302      29        99 ms  no
        Calendar 16331       9        62 ms  no
         Craigen 16957     256      5733 ms yes

Comment 8

[Gabriele Svelto [:gsvelto]]

Comment on attachment 8596553 [details] [review]
[PULL REQUEST] Add a script to easily trace applications

We don't really have an owner for this so r? Dave who's reviewed most changes to similar tools (such as b2g-info) and possesses impressive shell-fu skills.

Comment 9

[Dave Hylands [:dhylands]]

Comment on attachment 8596553 [details] [review]
[PULL REQUEST] Add a script to easily trace applications

Looks good - I made a few comments - all pretty minor, except for the hard-coded paths.

Comment 10

[Gabriele Svelto [:gsvelto]]

Thanks for the review! I've addressed the review comments - especially the hard-coded paths - and merged to b2g/master 57b7ad53740712d9390d4eb8ea0db45408c3a0b1

https://github.com/mozilla-b2g/B2G/commit/57b7ad53740712d9390d4eb8ea0db45408c3a0b1