Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: ecb227c4bef99549938b69d6eaaa85357c9444e0
https://github.com/WebKit/WebKit/commit/ecb227c4bef99549938b69d6eaaa85357c9444e0
Author: Yury Yarashevich <[email protected]>
Date: 2025-09-30 (Tue, 30 Sep 2025)
Changed paths:
M Source/WebCore/platform/graphics/cv/VideoFrameCV.mm
Log Message:
-----------
[VideoFrame] Avoid internal MT in Accelerate
https://bugs.webkit.org/show_bug.cgi?id=299819
Reviewed by Darin Adler.
VideoFrame construction in Safari shows a ~10x slowdown compared to CI builds,
seemingly due to a different allocator selected at runtime. Safari uses the
secure XZM allocator, while CI builds use the default allocator. A working
hypothesis is that because the secure allocator lazily zeroes memory on first
access, and Accelerate by default tiles the image and performs a multithreaded
copy, it introduces contention when multiple threads touch newly mapped pages
that must be zeroed. Since the secure allocator cannot be enabled predictably
for testing, a speculative fix is to disable multithreaded copy in Accelerate
by disallowing it from tiling the image via `kvImageDoNotTile`, which is
expected to eliminate contention on zeroing.
* Source/WebCore/platform/graphics/cv/VideoFrameCV.mm:
(WebCore::VideoFrame::createRGBA):
(WebCore::VideoFrame::createBGRA):
Canonical link: https://commits.webkit.org/300781@main
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