Improve async profiler startup feature list: "stackwalk"

RESOLVED WORKSFORME

Status

()

Core
Gecko Profiler
RESOLVED WORKSFORME
5 years ago
a year ago

People

(Reporter: jld, Assigned: jld)

Tracking

(Depends on: 1 bug)

Trunk
ARM
Gonk (Firefox OS)
Points:
---
Dependency tree / graph

Firefox Tracking Flags

(firefox26 affected, b2g-v1.2 affected)

Details

Attachments

(1 obsolete attachment)

(Assignee)

Description

5 years ago
So let's have a separate bug for turning on stack walking.  Bug 916106 is a source of concern.

+++ This bug was initially created as a clone of Bug #919078 +++

Starting the profiler asynchronously will be more useful if more features are enabled; in particular, "js" and "stackwalk" (or "leaf" on platforms where stack walking isn't available) are ones that I predict most users of the profiler will expect, and which the existing profiler-start-on-startup mechanism enables.
(Assignee)

Updated

5 years ago
status-b2g-v1.2: --- → affected
status-firefox26: --- → affected
(Assignee)

Comment 1

5 years ago
Bug 916106 has landed.  Is there anything else that needs to happen to turn on stack walking by default on ARM B2G?
Flags: needinfo?(bgirard)
What's the difference in CPU usage by having this on by default when idle?
Flags: needinfo?(bgirard)
(Assignee)

Comment 3

5 years ago
On keon, with the CPU set to maximum speed (1008 MHz) instead of being dynamically scaled:

Not profiling: 0.4%
Profiling with js+leaf: 6.7%
Profiling with js+stackwalk: 7.0%

That's the main thread of the main b2g process, sitting at the home screen, with the usual screen blanking on inactivity disabled.
(Assignee)

Comment 4

5 years ago
Forgot to mention: measured by adding the "utime" and "stime" fields (14 and 15) from /proc/N/stat, and measured over 300 seconds.
That's impressive. Alright lets turn it on!
(Assignee)

Comment 6

5 years ago
Created attachment 820502 [details] [diff] [review]
bug926610-stackwalk-on-async-hg0.diff
Attachment #820502 - Flags: review?(bgirard)

Updated

5 years ago
Attachment #820502 - Flags: review?(bgirard) → review+
(Assignee)

Comment 7

5 years ago
Comment on attachment 820502 [details] [diff] [review]
bug926610-stackwalk-on-async-hg0.diff

We're going to roll this into bug 925111, since that patch completely overwrites the code that would be changed here.
Attachment #820502 - Attachment is obsolete: true
(Assignee)

Updated

5 years ago
Depends on: 925111

Updated

5 years ago
Keywords: perf
Whiteboard: [c=profiling p= s= u=]
(Assignee)

Updated

5 years ago
Depends on: 938145
The profiler features for async profiler starts seem to be read from a "profiler.options" file and are no longer hardcoded.
But I think this method of starting the profiler from a signal handler was only ever used on B2G anyway and can probably removed.
Status: NEW → RESOLVED
Last Resolved: a year ago
Resolution: --- → WORKSFORME
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