987162 - Expand the systrace wiki docs

Status: RESOLVED WONTFIX

(Firefox OS Graveyard :: General, defect)

Description

[Andreas Pehrson [:pehrsons]]

See https://wiki.mozilla.org/B2G/Profiling#Profiling_with_systrace

Expected: instructions on how to enable and use systrace tracing on B2G

Result: "Better instructions coming"


I'd like to use this bug to track those instructions :)

Comment 1

[Andreas Pehrson [:pehrsons]]

Information that would be nice to have on the wiki:

I managed to get systrace to work but I had to enable tracing in the kernel by changing the defconfig for my device. What's the proper way, and what are the proper kernel config flags?

I didn't get any other processes than b2g to show up when profiling some Homescreen swiping. I had ultimately expected the Homescreen process to show up as well. Is that possible? Clearly a B2G app is not the same as an Android app (which is mentioned in systrace.py).

Benwa and Vincent, I know you have been involved in enabling systrace. Setting needinfo? on you to make you aware of this bug.

Comment 2

[Andreas Pehrson [:pehrsons]]

Attachment: trace.html.gz

Trace as mentioned in comment #1.

Comment 3

[Benoit Girard (:BenWa)]

I'm going to defer to vlin who knows systrace better then I do.

Comment 4

[Vincent Lin[:vilin]]

(In reply to Andreas Pehrson [:pehrsons] from comment #1)
> Information that would be nice to have on the wiki:
> 
> I managed to get systrace to work but I had to enable tracing in the kernel
> by changing the defconfig for my device. What's the proper way, and what are
> the proper kernel config flags?
> 
> I didn't get any other processes than b2g to show up when profiling some
> Homescreen swiping. I had ultimately expected the Homescreen process to show
> up as well. Is that possible? Clearly a B2G app is not the same as an
> Android app (which is mentioned in systrace.py).
> 
> Benwa and Vincent, I know you have been involved in enabling systrace.
> Setting needinfo? on you to make you aware of this bug.

Which device were you working on ?
Is it with Android JB 4.2 or 4.3 ?

I just follow steps here.
http://developer.android.com/tools/help/systrace.html#options-4.3

Sometimes, I also got B2G process being profiled only. Don't know why yet, but after reboot the device and profile again, all existing processes can be shown.

SDK version I'm working with for Nexus4 JB 4.3
adt-bundle-linux-x86_64-20131030

Comment 5

[Vincent Lin[:vilin]]

By the way, gecko code is tagged as 'gfx', so the command is for your reference.

./systrace.py --time=10 -o mynewtrace.html sched gfx

Comment 6

[Andreas Pehrson [:pehrsons]]

(In reply to Vincent Lin[:vilin] from comment #4)
> Which device were you working on ?
> Is it with Android JB 4.2 or 4.3 ?

It's Kitkat 4.4.


> I just follow steps here.
> http://developer.android.com/tools/help/systrace.html#options-4.3
> 
> Sometimes, I also got B2G process being profiled only. Don't know why yet,
> but after reboot the device and profile again, all existing processes can be
> shown.

All right, I'll try that.


Could you also add something on the kernel config?
I.e., when systrace.py complains over missing files in /sys/kernel/debug/tracing/, the kernel needs to be recompiled with additional configuration parameters to enable tracing.

I had luck with the following, but don't know which one did the trick.
CONFIG_FUNCTION_TRACER=y
CONFIG_FUNCTION_GRAPH_TRACER=y
CONFIG_STACK_TRACER=y
CONFIG_DYNAMIC_FTRACE=y
CONFIG_FTRACE=y

Comment 7

[Vincent Lin[:vilin]]

(In reply to Andreas Pehrson [:pehrsons] from comment #6)
> (In reply to Vincent Lin[:vilin] from comment #4)
> > Which device were you working on ?
> > Is it with Android JB 4.2 or 4.3 ?
> 
> It's Kitkat 4.4.
> 
> 
> > I just follow steps here.
> > http://developer.android.com/tools/help/systrace.html#options-4.3
> > 
> > Sometimes, I also got B2G process being profiled only. Don't know why yet,
> > but after reboot the device and profile again, all existing processes can be
> > shown.
> 
> All right, I'll try that.
> 
> 
> Could you also add something on the kernel config?
> I.e., when systrace.py complains over missing files in
> /sys/kernel/debug/tracing/, the kernel needs to be recompiled with
> additional configuration parameters to enable tracing.
> 
> I had luck with the following, but don't know which one did the trick.
> CONFIG_FUNCTION_TRACER=y
> CONFIG_FUNCTION_GRAPH_TRACER=y
> CONFIG_STACK_TRACER=y
> CONFIG_DYNAMIC_FTRACE=y
> CONFIG_FTRACE=y

That's weird. I've also heard from others that only B2G process is shown in KK. Unfortunately, after rebooting device, it still doesn't work. I'm still working on something based on JB, so haven't paid much attention to this issue on KK yet.

I would suggest to first verify the systrace function with Android instead of B2G.
Anyone complains about the same issue on Android in the internet ?

By the way, locally I encountered this issue and fixed it with reference to the link.
http://stackoverflow.com/questions/16644116/unable-to-view-html-trace-report-generated-by-systrace-tool-in-android-sdk

ni Jerry~
I know you're working on making FireFox browser be able to read Systrace dump.
Please see if it works well on the dump from KK.

Comment 8

[Vincent Lin[:vilin]]

Re-ni to the right Jerry(hshih).
Sorry to bother jshih.

Comment 9

[Jerry Shih[:jerry] (UTC+8) (inactive)]

Sorry for late reply.
I will find a nexus5 device to try.

Comment 10

[Jerry Shih[:jerry] (UTC+8) (inactive)]

(In reply to Vincent Lin[:vilin] from comment #7)
> That's weird. I've also heard from others that only B2G process is shown in
> KK. Unfortunately, after rebooting device, it still doesn't work. I'm still
> working on something based on JB, so haven't paid much attention to this
> issue on KK yet.
> 

Yes, I have confirmed with Vincent. The android atrace doesn't output other thread's profile data. Thus, we can't see the other thread in the tool view.
We will check command usage, device setting... etc to identify this problem.

Comment 11

[Mason Chang [Inactive] [:mchang]]

Hi Jerry, any luck on being able to produce systrace output with multiple processes? Thanks!

Comment 12

[Mason Chang [Inactive] [:mchang]]

Attachment: mynewtrace_setting.html

I tried running systrace on b2g but it does not work as expected. I flashed my Nexus 4 to a stock Jelly Bean image from AOSP, as suggested from comment 7 and systrace worked just fine on Android. I tried a fresh copy of b2g and reflashed the nexus 4 to no avail. Interestingly, I also get random threads in the b2g process showing up in my trace files. Only Vsync and the compositor thread are reliable. I also sometimes see 2-3 CPUs depending on the profile trace. Do we have a general systrace bug?

Comment 13

[Jerry Shih[:jerry] (UTC+8) (inactive)]

Hi Mason,
I can use nexus4 with JB to dump the multiple processes systrace data.
I will confirm again for the steps in the wiki doc.

Comment 14

[Jerry Shih[:jerry] (UTC+8) (inactive)]

[:ctai] finds the reason that why we can't get the non-main process profile info.
There are some conditions that the non-main process doesn't fit. I think [:ctai] can fix this problem soon.

Comment 15

[Chia-hung Tai [:ctai :ctai_mozilla :cht]]

Since Bug 1015860 is landed, I updated the wiki page https://wiki.mozilla.org/FirefoxOS/Performance/Profiling.
Now we can see the systrace result in content process.

Comment 16

[Jerry Shih[:jerry] (UTC+8) (inactive)]

Hi Mason and Andreas,
We update the wiki page https://wiki.mozilla.org/FirefoxOS/Performance/Profiling .
And now we can get all process profile data.

Comment 17

[Mason Chang [Inactive] [:mchang]]

Great, thanks for resolving this Jerry.