Revert of Oilpan: always shrink tail-allocated backing storage. (patchset #2 id:20001 of https://codereview.chromium.org/1393863004/ )
Reason for revert:
Suspect that this change has caused assertion failures on
Oilpan+Windows+Debug bot.
http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win%20Oilpan%20%28dbg%29/builds/2955
(Builds are purple because they quit early due to
too many crashes.)
Crash logs look like:
02:49:04.570 1008 ASSERTION FAILED: header->payloadSize() > newSize
02:49:04.570 1008 Backtrace:
02:49:04.570 1008 blink::NormalPageHeap::shrinkObject [0x084A1504+148]
02:49:04.570 1008 blink::HeapAllocator::backingShrink [0x0849AE8A+394]
02:49:04.570 1008 blink::HeapAllocator::shrinkVectorBacking [0x0849B064+20]
02:49:04.570 1008 WTF::VectorBuffer<blink::Member<blink::Node>,0,blink::HeapAllocator>::shrinkBuffer [0x189E87A6+134]
02:49:04.570 1008 WTF::Vector<blink::Member<blink::Node>,0,blink::HeapAllocator>::shrinkCapacity [0x189E8BA6+102]
02:49:04.570 1008 WTF::Vector<blink::Member<blink::Node>,0,blink::HeapAllocator>::shrinkToFit [0x19A6E65F+31]
02:49:04.570 1008 blink::DistributedNodes::shrinkToFit [0x19A6E686+22]
(snip)
Original issue's description:
> Oilpan: always shrink tail-allocated backing storage.
>
> When shrinking backing storage allocations, some care is taken not to
> introduce excessive fragmentation and/or limit later expansion of the
> same object. That logic does not need to apply if the backing store is
> at the tail of the current heap chunk: unconditionally reset the
> allocation point, if it is.
>
> R=haraken
> BUG=420515
>
> Committed: https://crrev.com/afa3e61596ebb5d648a6e9923de85534926d27fa
> Cr-Commit-Position: refs/heads/master@{#353321}
TBR=oilpan-reviews@chromium.org,haraken@chromium.org,sigbjornf@opera.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=420515
Review URL: https://codereview.chromium.org/1395493008
Cr-Commit-Position: refs/heads/master@{#354243}
3 files changed
