Closed Bug 1659453 Opened 5 months ago Closed 5 months ago

Accelerate font fallback searches using family character map

Categories

(Core :: Layout: Text and Fonts, enhancement, P2)

enhancement

Tracking

()

VERIFIED FIXED
81 Branch
Tracking Status
firefox-esr78 --- fixed
firefox81 --- verified

People

(Reporter: jfkthame, Assigned: jfkthame)

References

(Blocks 1 open bug)

Details

Attachments

(1 file)

Spun off from https://bugzilla.mozilla.org/show_bug.cgi?id=1657892#c35; see discussion & profiles in that bug for background.

This is the non-shared-fontlist version of bug 1658207, so will be largely obsolete once the new fontlist is preffed on everywhere, but in the meantime we should do this.

Pushed by jkew@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/1f45c61b2fde
Accelerate gfxFontFamily::SearchAllFontsForChar by setting up the family charmap. r=lsalzman
Status: NEW → RESOLVED
Closed: 5 months ago
Resolution: --- → FIXED
Target Milestone: --- → 81 Branch

Verified fix on 81.0a1 (2020-08-19) on macOS 10.15.6 and the wiki page zooms correctly.

Status: RESOLVED → VERIFIED
Regressions: 1660232

== Change summary for alert #26758 (as of Thu, 20 Aug 2020 10:42:19 GMT) ==

Improvements:

14% perf_reftest_singletons bidi-resolution-1.html linux64-shippable-qr opt e10s stylo 390.81 -> 335.50
14% perf_reftest_singletons bidi-resolution-1.html linux64-shippable opt e10s stylo 351.79 -> 302.45
14% perf_reftest_singletons bidi-resolution-1.html linux64-shippable-qr opt e10s stylo 391.70 -> 336.87

For up to date results, see: https://treeherder.mozilla.org/perf.html#/alerts?id=26758

Comment on attachment 9170391 [details]
Bug 1659453 - Accelerate gfxFontFamily::SearchAllFontsForChar by setting up the family charmap. r=lsalzman

ESR Uplift Approval Request

  • If this is not a sec:{high,crit} bug, please state case for ESR consideration: This patch has proved very useful in mitigating a significant performance issue documented in bug 1677272
  • User impact if declined: Thunderbird esr78 users on macOS Big Sur suffer display delays of several seconds. Perhaps Firefox ESR will also benefit, but have not searched bugzilla for applicable reports.
  • Fix Landed on Version: 81
  • Risk to taking this patch: Low
  • Why is the change risky/not risky? (and alternatives if risky): Patch has been shipped in Firefox releases for several months, and no regressions filed against it.

No alternative has been found to date, other than not updating to Big Sur.

  • String or UUID changes made by this patch:
Attachment #9170391 - Flags: approval-mozilla-esr78?
Blocks: 1677272

Jonathan, do you have any concerns about taking this in ESR?

Flags: needinfo?(jfkthame)

(In reply to Ryan VanderMeulen [:RyanVM] from comment #7)

Jonathan, do you have any concerns about taking this in ESR?

No concerns here; it's a simple patch that gives a substantial improvement in some cases, and introduces minimal risk. I'd be in favor of taking it.

Flags: needinfo?(jfkthame)

Comment on attachment 9170391 [details]
Bug 1659453 - Accelerate gfxFontFamily::SearchAllFontsForChar by setting up the family charmap. r=lsalzman

Thanks for the input. Approved for 78.7esr.

Attachment #9170391 - Flags: approval-mozilla-esr78? → approval-mozilla-esr78+
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