Closed Bug 1365278 Opened 3 years ago Closed 3 years ago
Many calls from gfx
Font::Get Shaped Word<..> to Telemetry::Accumulate
This is with a Stylo enabled build, with 8 stylo threads. Loading the Obama wikipedia web page: https://en.wikipedia.org/wiki/Barack_Obama Profiling with Callgrind shows the following 61,725 total calls to mozilla::Telemetry::Accumulate of which 40,107 are from gfxFont::GetShapedWord<unsigned char> 5,240 are from gfxFont::GetShapedWord<char16_t> So in total 45,347 of 61,725 (73.4%) of the calls come from this one function. It also seems a rather excessive number of Telemetry calls given that this is for the display of this one web page. Given that each such call causes a pthread_mutex_lock and unlock pair, it's potentially of concern from a parallel-performance perspective.
I think we should just remove these telemetry counters. It was good to check on cache behavior seen in the wild back when this was being implemented, but they're not really telling us anything useful on an ongoing basis, and this is pretty hot code where we shouldn't do extra work if we can help it.
Attachment #8872082 - Flags: review?(milan)
3 years ago
Attachment #8872082 - Flags: review?(milan) → review+
https://hg.mozilla.org/integration/mozilla-inbound/rev/adc68cbe1295500e348dd3ff8e6737f7b77006b0 Bug 1365278 - Remove WORD_CACHE_* telemetry probes that provide little value for their cost. r=milan
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