1520294 - Optimize nsFilterInstance allocation

Status: RESOLVED FIXED

(Core :: SVG, defect, P3)

Description

[Daniel Holbert [:dholbert]]

See bug 1427417 comment 10 - it seems we've got some nsFilterInstance malloc/free churn shown in this profile: https://perfht.ml/2Ddr9dH

This is when hovering at https://kangax.github.io/compat-table/esnext/ , without webrender enabled.

Comment 1

[Olli Pettay [:smaug][[e-mail]]]

Should https://searchfox.org/mozilla-central/rev/c21d6620d384dfb13ede6054015da05a6353b899/gfx/src/FilterSupport.h#464 use AutoTArray ?

Comment 2

[Olli Pettay [:smaug][[e-mail]]]

and https://searchfox.org/mozilla-central/rev/c21d6620d384dfb13ede6054015da05a6353b899/gfx/src/FilterSupport.h#467 too ?
I don't know how large those arrays normally are.

Comment 3

[Robert Longson [:longsonr]]

(In reply to Olli Pettay [:smaug] from comment #2)

and https://searchfox.org/mozilla-central/rev/c21d6620d384dfb13ede6054015da05a6353b899/gfx/src/FilterSupport.h#467 too ?
I don't know how large those arrays normally are.

Should be no more than 2. Most commonly 1, rarely 0 or 2.

Comment 4

[Olli Pettay [:smaug][[e-mail]]]

The obvious fix to replace those with AutoTArray<, 2> crashes. Something very bogus looking objects in FilterSupport::ComputePostFilterExtents. I assume some copy or move constructor doens't quite work. I'll look tomorrow.

Comment 5

[Olli Pettay [:smaug][[e-mail]]]

Attachment: less_allocations_in_FilterPrimitiveDescription.diff

This helps a bit, but the filter code seems to be rather malloc heavy.
For example nsFilterInstance::ComputePostFilterExtents and nsCSSFilterInstance::SetBounds

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/cee37d07397c
make FilterPrimitiveDescription usage a tad less malloc heavy, r=mstange

Comment 7

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/cee37d07397c