1460678 - Improve |mach doc| performance

Status: REOPENED

(Developer Infrastructure :: Source Documentation, enhancement)

Description

[Andrew Halberstadt [:ahal]]

I think there might be some low-hanging fruit to improve the |mach doc| performance (which is generally really terrible).

A couple ideas:
1. Upgrade sphinx to latest version
2. Use sphinx's -J argument (not sure how much of an impact this has)
3. Build regular and python API docs in parallel (these are two separate sphinx invocations on unrelated directories that happen serially)
4. Be smarter about caching results and only re-building what we need to. Sphinx normally does this automatically, but since we move the entire doctree from the srcdir->objdir each time, it thinks everything has always changed. This might be better off in a follow-up.

Comment 1

[Andrew Halberstadt [:ahal]]

Another idea:
Make a sphinx build backend so we don't need to re-read moz.build each time. Rebuilds triggered via the livereload server already cache this result however, so it might not be as worthwhile.

Comment 2

[Anurag Aggarwal]

Hi Andrew,

For 1, I guess the sphinx is already the latest version i.e. 1.8.5 as installed using pipenv
For 2, Can you please link me to the argument you are referring.
For 3, I was thinking of using ThreadPoolExecutor in light of ProcessPool. Am I wandering right?

Comment 3

[Andrew Halberstadt [:ahal]]

Hi Anurag, sorry I missed your comment.

This bug is currently earmarked for a GSoC internship (he may be about to start working on it shortly). But since there are multiple things to work on here, maybe we could split it out into smaller bugs and divide things up in a way that won't cause you to step on each other's toes. So just hang on for now if you're still interested and I'll let you know.

Comment 4

[Anurag Aggarwal]

No problem and yes I am still interested. Please let me know, if you have anything I can work on. :D

Comment 5

[Shivam Singhal [ :championshuttler ]]

Attachment: Bug 1460678 - Improve mach doc performance, use sphinx's -J argument. r=ahal

Comment 6

[Shivam Singhal [ :championshuttler ]]

Attachment: Bug 1460678 - Build regular and python API docs in parallel. r=ahal

Depends on D41058

Comment 7

[Narcis Beleuzu [:NarcisB]]

:ahal , can you please review D41062.
:championshuttler, I removed the "checkin-needed". Please add it after the patch is r+ .

Comment 8

[Shivam Singhal [ :championshuttler ]]

Narcis, thanks. It will be reviewed soon. Clearing ni for :ahal.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/07e30c57a8e6
Improve mach doc performance,  use sphinx's -J argument. r=ahal

Comment 10

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/07e30c57a8e6

Comment 11

[Sylvestre Ledru [:Sylvestre]]

1. Upgrade sphinx to latest version

Moving from 1.8.5 => 2.2.2 isn't improving much the time.

./mach doc --no-serve  125,26s user 10,34s system 158% cpu 1:25,70 total

=>

./mach doc --no-serve  122,69s user 8,54s system 184% cpu 1:11,11 total

Bug 1601612 for the implementation

Comment 12

[BugBot [:suhaib / :marco/ :calixte]]

The leave-open keyword is there and there is no activity for 6 months.
:rstewart, maybe it's time to close this bug?

Comment 13

[Sylvestre Ledru [:Sylvestre]]

Actually, we will work on that.
emil, gsoc student, might have some time to have a look.

Comment 14

[Sylvestre Ledru [:Sylvestre]]

Attachment: Profile by number of call

Comment 15

[Sylvestre Ledru [:Sylvestre]]

Attachment: Profile by interval time

Comment 16

[Sylvestre Ledru [:Sylvestre]]

To generate this:

diff --git a/mach b/mach
--- a/mach
+++ b/mach
@@ -65,17 +65,17 @@ py2commands="
 
 run_py() {
     # Try to run a specific Python interpreter. Fall back to the system
     # default Python if the specific interpreter couldn't be found.
     py_executable="$1"
     shift
     if which "$py_executable" > /dev/null
     then
-        exec "$py_executable" "$0" "$@"
+        exec "$py_executable" -m cProfile -s ncalls "$0" "$@"
     elif [ "$py_executable" = "python2.7" ]; then
         exec python "$0" "$@"
     else
         echo "This mach command requires $py_executable, which wasn't found on the system!"
         exit 1
     fi
 }

And run with

./mach -v doc --no-serve &> foo2.log

Comment 17

[Sylvestre Ledru [:Sylvestre]]

To generate better infos:
use:

        exec "$py_executable" -m cProfile -o machdoc.cprof -s ncalls "$0" "$@"

in mach doc

then

pyprof2calltree -k -i machdoc.cprof

More on my buddy website:
https://julien.danjou.info/guide-to-python-profiling-cprofile-concrete-case-carbonara/

Comment 18

[Bukola Felicia Akinnadeju]

Is there still something that needs to be fixed on this bug that i could lay my hands on?

Comment 19

[Andrew Halberstadt [:ahal]]

Perhaps you could fix some of the warnings that show up with ./mach doc (ideally there shouldn't be any warnings). There aren't any bugs on file, but you can file one once you've picked a few warnings to tackle.

Comment 20

[Sylvestre Ledru [:Sylvestre]]

It is getting worse and worse!

I run the python profiler. It seems that, for a normal doc build, we are calling 981 869 277 times a function called "sentry_patched_popen_communicate".

So, disabling sentry (export DISABLE_TELEMETRY=1) dropped the time from
./mach doc --no-serve &> foo.log 383,58s user 141,69s system 64% cpu 13:37,21 total
to
./mach doc --no-serve &> foo.log 136,96s user 7,55s system 144% cpu 1:40,21 total

Comment 21

[Sylvestre Ledru [:Sylvestre]]

Attachment: Bug 1460678 - doc: Disable sentry as it adds significant overhead r?#firefox-source-docs-reviewers

Comment 22

[Sylvestre Ledru [:Sylvestre]]

Attachment: Bug 1460678 - doc: ride along bump sentry r?#firefox-source-docs-reviewers

Depends on D123795

Comment 23

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/925cdf01fd85
doc: Disable sentry as it adds significant overhead r=mhentges
https://hg.mozilla.org/integration/autoland/rev/775e23b5bf52
doc: ride along bump sentry r=mhentges

Comment 24

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/925cdf01fd85
https://hg.mozilla.org/mozilla-central/rev/775e23b5bf52

Comment 25

[BugBot [:suhaib / :marco/ :calixte]]

The leave-open keyword is there and there is no activity for 6 months.
:Sylvestre, maybe it's time to close this bug?
For more information, please visit auto_nag documentation.

Comment 26

[Sylvestre Ledru [:Sylvestre]]

Yeah, still slow... but I don't have a better solution for now

Comment 27

[Sylvestre Ledru [:Sylvestre]]

to profile it:
python3 -m cProfile -o machdoc.cprof -s ncalls mach doc
python3 -m snakeviz machdoc.cprof
or
pyprof2calltree -k -i machdoc.cprof

Comment 29

[ogiorgis]

Attachment: Bug 1460678 - upgrade sphinx to version 5 r=#firefox-source-docs-reviewers

Depends on D173680

Comment 30

[Phabricator Automation]

Comment on attachment 9325204 [details]
Bug 1460678 - upgrade sphinx to version 5 r=#firefox-source-docs-reviewers

Revision D173704 was moved to bug 1824659. Setting attachment 9325204 [details] to obsolete.