• Michael Lippautz's avatar
    Revert "cppgc: Rework prefinalizers" · f46c4858
    Michael Lippautz authored
    This reverts commit cf25b3bc.
    
    Reason for revert: https://crbug.com/1307471. TraceTrait must only be used during marking.
    
    Original change's description:
    > cppgc: Rework prefinalizers
    >
    > Move the check for whether an object is live or dead out of the
    > prefinalizer trampoline. Moving it into the backend allows for
    > inlining the check which avoids a call to the trampoline for live
    > objects.
    >
    > On catapult benchmarks (e.g. cnn:2021, nytimes:2020), there's often
    > ~2k finalizers registered. In order to avoid memory overhead in the
    > range of a few KB, we store the fact whether the object points to the
    > base object payload in the LSB of the pointer. For caged builds this
    > is replaced with just storing the index into the cage for both object
    > and base object payload.
    >
    > Locally saves around ~10% of atomic sweeping processing time which is
    > in the order of .05ms.
    >
    > Bug: v8:12698
    > Change-Id: I198205a6b1d57fc2df821ee4e73e53dc6f825ff5
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3497764
    > Reviewed-by: Omer Katz <omerkatz@chromium.org>
    > Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
    > Cr-Commit-Position: refs/heads/main@{#79442}
    
    Bug: v8:12698, chromium:1307471
    Change-Id: I5c4e70d46cb99af66c77f0c013625b6af6c6eb8e
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3535781
    Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
    Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
    Cr-Commit-Position: refs/heads/main@{#79527}
    f46c4858