1474559 - Asan opt x64 build not loading pages on Win 7 x64

Status: NEW

(Firefox Build System :: General, defect)

Description

[laszlo.bialis]

[Affected versions]:
Buidl ID: 20180710001201 version 63.0a1

[Affected platforms]:
Windows 7 x64

[Steps to reproduce]:
1. Download target.zip from https://tools.taskcluster.net/index/gecko.v2.mozilla-central.latest.firefox/win64-asan-opt
2. Open the build with a new profile
3. Load any webpage

[Expected result]:
Page should load correctly.

[Actual result]:
Nothing seems to happen, no activity is shown in the browser build (no spinning wheel or any othe load sign).

Comment 1

[laszlo.bialis]

Adding need info for [e-mail] as agreed.

Comment 2

[laszlo.bialis]

Tested with the same build on Win 10 and Win 8.1 and pages load correctly on the same build on these os'es.

Comment 3

[(Away)]

I was able to load pages with an ASan build on Windows 7 SP1 x64.

It's going to be quite difficult to diagnose this without sitting in front of your PC. Can you please share as much information about this machine as possible? about:support, crash report data, etc. Anything even remotely relevant would be great. Better to have too much info than not enough.

It may also be helpful to try this on a few other Win7 machines to rule out a single-PC issue. Maybe even on a completely clean OS installation if you have time.

Comment 4

[laszlo.bialis]

Retested the issue on several PC's with Win7 with following results:

1. PC with Win 7 Professional SP1 x32 / build 7601
   Processor: Intel I5-3470 CPU @ 3.20GHZ
   RAM: 8GB
   both asan and Fx 53 07/10/2018 work

2. PC with Win7 Professional N SP1 X64 build 7601
   AMD FX(tm)-8320 Eight-Core Processor 3.5GHz
   8GB RAM
   ASAN x32 build works, x64 build works partially (only one tab is loading content), Fx63 07/11/2018 works

3. PC with Win7 Professional SP1 X64 build 7601
   Intel i3-5005U CPU @ 2.0GHZ
   4GB RAM
   ASAN x32 build works, x64 build doesn't work at all, Fx63 07/11/2018 works

PC from example 3 was used yesterday when the bug was filed. Since the build is not working at all I can't attach an about support form this PC. If it helps I can submit an about:support from the FX63. 
Attaching an about:support file made from PC from example 2, still no about:crashes can be attached as the ASAN build won't allow that. 
Removed the blocker flag and updated summary as Clang was introduced in FX63 and that works on all PC's that I've tested on.

Comment 5

[(Away)]

Where did you find an ASan x32 build? Our automation should not be producing those.

Comment 6

[(Away)]

Thanks for those PC specs! I think this may be a memory requirement.

I have a fresh Win7 installation on a VM where I adjusted the RAM size.
* 3GB doesn't load pages
* 4GB loads some pages, churns a lot
* 5GB seems ok with simple pages, but maybe larger ones would fail

This isn't too surprising as ASan's functionality needs lots of memory.

Comment 7

[laszlo.bialis]

I've took the ASan x32 build from here https://tools.taskcluster.net/index/gecko.v2.mozilla-central.latest.firefox/win32-opt

Comment 8

[(Away)]

> https://tools.taskcluster.net/index/gecko.v2.mozilla-central.latest.firefox/win32-opt

That's not an ASan build (there is no "-asan" in the name).

Comment 9

[laszlo.bialis]

We were just using taskcluster builds to test clang-cl builds until it landed on mc - for win7 we used x32(https://tools.taskcluster.net/index/gecko.v2.mozilla-central.latest.firefox/win32-opt ). Therefore, in the above comment, my point was to underline that the bug on w7x64 is an ASAN issue not a clang-cl one. Apologies if I was missleading.

Comment 10

[(Away)]

Ok. So let's go back to the memory size...

Can you try on the 8GB machine on a fresh reboot, with all other applications and background services closed?

Do you have any 16GB machines to try?

Comment 11

[laszlo.bialis]

Attachment: memory-report.json.gz

Comment 12

[laszlo.bialis]

Attachment: memory-report2.json.gz

Comment 13

[laszlo.bialis]

Attachment: command prompt.txt

Comment 14

[laszlo.bialis]

Hey David,

I've redone some testing today on the PC with Win7 Professional N SP1 X64 build 7601 AMD FX(tm)-8320 Eight-Core Processor 3.5GHz
8GB RAM.

It seems the issue is caused indeed by the memory size. 

At first I've retested with the swap space set to the initial 8173 MB and the build only worked with one tab as yesterday (any other tab opened didn't load anything). I've also monitored the memory usage, while prior to starting the build the usage was between 1.5-2.5 GB after the I've started the build the memory usage went as far as 4.5-5.5 GB from the initial 8GB RAM (with all background services closed). I've also done a memory report attached file "memory-report.json.gz" and I'm also attaching the info from the command prompt window "command prompt.txt", hoping this would be of help.

At the second try I've modified the swap space size to 16346 MB and the build seemed to work as expected, opened three different tabs, every page loaded as it should, no error received. The memory usage seemed also a bit smaller, between 3.5-4.5 GB. Attaching a "memory-report2.json.gz" file also.

At a third run I've reset everything at the initial state and the issue reappeared.

Comment 15

[(Away)]

Thank you for the information.

I don't really know what to do with this bug now. On the one hand, this is just ASan being ASan. On the other hand, one could argue that it's a bug to fail in this non-obvious way.

So I don't want to immediately resolve this as wontfix, but it's not really a priority to work on, either. As long as ASan tests in CI are happy, we have bigger fish to fry.