• Dan Elphick's avatar
    Revert "[heap] Make ReadOnlySpace use bump pointer allocation" · f78d69fa
    Dan Elphick authored
    This reverts commit 81c34968 and also
    490f3580 which depends on the former.
    
    Reason for revert: Break CFI tests in chromium https://ci.chromium.org/p/chromium/builders/ci/Linux%20CFI/17438
    Original change's description:
    > [heap] Make ReadOnlySpace use bump pointer allocation
    >
    > This changes ReadOnlySpace to no longer be a PagedSpace but instead it
    > is now a BaseSpace. BasicSpace is a new base class that Space inherits
    > from and which has no allocation methods and does not dictate how the
    > pages should be held.
    >
    > ReadOnlySpace unlike Space holds its pages as a
    > std::vector<ReadOnlyPage>, where ReadOnlyPage directly subclasses
    > BasicMemoryChunk, meaning they do not have prev_ and next_ pointers and
    > cannot be held in a heap::List. This is desirable since with pointer
    > compression we would like to remap these pages to different memory
    > addresses which would be impossible with a heap::List.
    >
    > Since ReadOnlySpace no longer uses most of the code from the other
    > Spaces it makes sense to simplify its memory allocation to use a simple
    > bump pointer and always allocate a new page whenever an allocation
    > exceeds the remaining space on the final page.
    >
    > Change-Id: Iee6d9f96cfb174b4026ee671ee4f897909b38418
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2209060
    > Commit-Queue: Dan Elphick <delphick@chromium.org>
    > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#68137}
    
    TBR=ulan@chromium.org,delphick@chromium.org
    
    # Not skipping CQ checks because original CL landed > 1 day ago.
    
    Change-Id: I68c9834872e55eb833be081f8ff99b786bfa9894
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2232552
    Commit-Queue: Dan Elphick <delphick@chromium.org>
    Reviewed-by: 's avatarDan Elphick <delphick@chromium.org>
    Reviewed-by: 's avatarUlan Degenbaev <ulan@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#68211}
    f78d69fa
basic-memory-chunk.cc 2.12 KB