• Dominik Inführ's avatar
    Revert "Use list of invalidated objects for old-to-new refs" · 9a9ba762
    Dominik Inführ authored
    This reverts commit 60843b42.
    
    Reason for revert: TSAN detected issue between Scavenge workers.
    One task could invoke RefillFreeList(), while the other task iterates the remembered set of a swept page.
    
    Original change's description:
    > Use list of invalidated objects for old-to-new refs
    > 
    > Instead of inserting "deletion" entries into the store buffer, keep a
    > list of invalidated objects to filter out invalid old-to-new slots.
    > 
    > The first CL https://crrev.com/c/1704109 got reverted because both the
    > sweeper and the main task were modifying the invalidated slots data
    > structure concurrently. This CL changes this, such that the sweeper
    > only modifies the invalidated slots during the final atomic pause when
    > the main thread is not running. The sweeper does not need to clean this
    > data structure after the pause, since the "update pointers" phase
    > already removed all invalidated slots.
    > 
    > The second CL https://crrev.com/c/1733081 got reverted because the
    > sweeper might find more free space than the full GC before it. If an
    > object shrinks after the pause but before the sweep, the invalidated
    > object might span free memory and potentially new allocated objects.
    > Therefore shrink invalidated objects when processing swept pages on
    > the main thread. Also clean recorded slots in the gap.
    > 
    > TBR=petermarshall@chromium.org
    > 
    > Bug: v8:9454
    > Change-Id: I80d1fa3bbc24e97f7c97a373aaad66f105456f12
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1751795
    > Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
    > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#63239}
    
    TBR=ulan@chromium.org,hpayer@chromium.org,dinfuehr@chromium.org
    
    Change-Id: I9c6a371ebe36a1873acbe0d6c6a75dd2f5a55f4e
    No-Presubmit: true
    No-Tree-Checks: true
    No-Try: true
    Bug: v8:9454
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1760817Reviewed-by: 's avatarDominik Inführ <dinfuehr@chromium.org>
    Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#63253}
    9a9ba762
string.cc 54.9 KB