Performance/Snappy/2012-01-12

• taras blogged on slow sessions - nobody wants to give up their session file
• no visibility into what sessions consist of
• maybe need add-on for visualizing session contents
• maybe one for scrubbing session contents - leavinng only structure
• taras suspects slow tab animations for large sessions
• need data from the wild for confirmation of specific pages causing problems
• TODO: file bug on slow tab animations - could construct 900 tab session to test for example
• something
• dmandelin: sqlite is close to top of list of jank causes
• session restore sometimes
• gc is huge cause of short/middle length jank
• main thread IO shows up, don't know specifics yet
• some locks on main thread - 800 - 3000ms
• cycle collector sometimes serious, sometimes not
• taras said d2d drawing is a cause
• youtube unusable for some people
• flash and plugin stuff - anecdotally ("disable flash, everything is fine")
• github: copy/paste icon for each commit, is flash.
• jquery check for java enabled
• something about painting, addons and d2d with jeffm (gah, i should turn off irc during note-taking)
• cycle collector update from jst
• lots of work going on, landings soon
• much improvement
• taras: do we need telemetry to see if thigns actually improve after landing
• jst: seeing local improvements, but real data wouldn't hurt
• jst: 4x improvements
• yay smaug and andrewm for working on this
• leaks no longer impact cc times w/ these patches
• landings in next couple of weeks
• dman: would be nice if telemetry showed median, more contextual stats -
• notetaker got distracted again
• some discussion about Chrome's approach to zerocycle
• some smaug patches point at some approaches to killing js cycles
• dman: what would be "good enough" for cc pauses
• smaug investigates >50ms pauses
• adblock+ exhibiting oddly long pauses
• jst: should target 60ms so always getting 60fps?
• dman: "can you watch a movie w/o jank?" eg
• jst: make things more incremental everywhere
• jst: future where we can render video through a long cc/gc pause
• rjes: yes, that's required for things like webrtc
• andrew: current telemetry doesn't catch things like gc/cc regressions
• dman: lots of times zero objects collected - does that mean we collect too often?
• and: every time we gc we follow w/ cc, which is overkill
• jst: history on scheduling is ungood - could improve

projects

• dman: what should js profiling measure?
• taras: high level, should be able to do tab-level accounting
• cumulative time-spent in tab
• jst: might be useful to have Process Explorer style view of tabs and resources used
• eg: "time in js", etc, auto-refreshing
• reflows
• taras: when can you assign someone on this
• jst: dunno yet.
• timers on background tabs
• something about coalescing all the timers
• dman: scheduling the timers to de-jankify (<- new word win)
• jst: walking the balance between jankiness and batter
• dman: sample and predict how long it'll take the timers to run
• taras: could unclamp when possible
• and: scheduling cc based on previous patterns - slow down in bad state, etc
• telemetry: no front-end telemetry update
• dman: what's top thing should measure?
• dietrich: maybe should base that on support and anecdotal complaints
• taras: should be session restore data
• cache: compression landed
• dman: know anything about cache lock?
• nick: shouldn't still happen
• profiler
• what's status on getting stack-walking working on mac
• yes, some progress
• no work on linux yet - just resource-less there
• graphics harness for fps - harness, api?
• jeff sending link to taras to blog
• nondestructive chromehang
• scrolling
• jared: patches in review cycle for some
• clicking quickly: waiting on new patch
• interruptible js: some new crazy ideas, but nothing concrete, so kinda drop for now
• peptest: waiting for changes to land - won't be on by default
• waiting to get sps stuff into peptest for developer diagnosis tool
• test for session restore - how responsive while restoring session
• not much can do if causing reflows, but sstill useful data
• slowsql no updates
• inline autocomplete: coming, needs final reviews
• no new triage until progress on existing projects
• bye bye