TPEGFX/Notes

Crash

• offsite sharing - crash
  • Reading crash report on soccorow (kevin)
    • Find the correlation
    • Understand crash reason, crash address
  • A look into mini dump/symbols/crash report (vincent)
    • how to load mini dump/symbols
  • useful windbg/gdb/lldb commands
    • (lldb) br com add 1 //executes commands when breakpoint was hit
    • (windbg) dt !xul:nsfont
    • (windbg) !analyze -v
  • case study
    • https://bugzilla.mozilla.org/show_bug.cgi?id=1353657 (vincent)
    • https://bugzilla.mozilla.org/show_bug.cgi?id=1346421(TBD)
    • https://bugzilla.mozilla.org/show_bug.cgi?id=1357734#c12(ethan)

Testing

• [pchang] run GTest subset
  • ./mach gtest Layers.*
  • GTEST_FILTER='Layers*' MOZ_RUN_GTEST=1 ./mach run --debug //use debugger to debug GTest

• [Michael Leu] - My workflow of building environments for reproducing bugs
  • https://drive.google.com/file/d/0B29kx4ibiTBgN0JBTVBiVEh0TUU/view

Misc

• [ethan] Canvas performance
  • http://www.bilibili.com/video/av105005/
• [Michael] FPS adjustment
  • layout.frame_rate in about:config (-1 means default which is 60, 1000 at maximum)
• [pchang] Use gecko profiler with symbols
  • ac_add_options --enable-profiling
• [pchang] Enable CPU profiling when use release build
  • export MOZ_DEBUG_SYMBOLS=1
  • ac_add_options --enable-debug-symbols
• [pchang] Enable ASAP mode
  • layout.frame_rate: 0
  • docshell.event_starvation_delay_hint: 1
• [pchang] dump log with timestamp 5 for debug 2 for Err
  • MOZ_LOG=Layers:5,timestamp ./mach run 2>&1|tee omta.log
• [pchang] dump stderr to console on windows
  • ./mach run 2>&1|tee console.out
• [Jerry] dump call stack for NS_ASSERTION() or NS_WARNING()
  • Set prefix for stack message.
    • https://dxr.mozilla.org/mozilla-central/rev/632e42dca494ec3d90b70325d9c359f80cb3f38a/xpcom/base/nsTraceRefcnt.cpp#845
  • Set stack unwind number
    • https://dxr.mozilla.org/mozilla-central/rev/632e42dca494ec3d90b70325d9c359f80cb3f38a/xpcom/base/nsTraceRefcnt.cpp#880
  • XPCOM_DEBUG_BREAK="stack" ./mach run

Triage

• [vliu] Triage flow listed.
  • Try to reproduce
    • Add keyword 'reproducible' if you can reproduce
    • Ask reporter set layers.acceleration.disabled as true to try again(depends)
    • Enable/Disalbe ANGLE on windows
    • Compare the difference between on/off e10s.
    • Tried to change the preferences to observe.
      • If the issue relatives to painting or text, you can try to change the backend in about:config
        • gfx.canvas.azure.backends
        • gfx.content.azure.backends
      • nglayout.debug.paint_flashing
      • layers.draw-borders
  • Ask for about:support
    • Ask for about:memory if memory related
  • ni? people or mgr to help you
  • land needed printing message for this bug to observe more information.(this action is providing solution not doing the triage)
  • Change priority to P1-3 with reason
  • Add gfx-noted if there is nothing you can follow up
• Ways to observe occurrence for triage bug.
  • Crash report contains Volume to count for crash rate. There is 10 times of Volume increase between each FF version.
    • Install addon bugzilla-socorro-lens can easily see crash rate in graphic view on that bug.
      • bugzilla-socorro-lens
  • For Intermittent bug, Orange Factor counts for occurrence rate for that bug you observed.
    • Orangefactor
• A useful link to help you reading crash report.
  • Understanding-crash-reports
• refer keyword here https://wiki.mozilla.org/Platform/GFX/TriageSchedule#Keywords