Force Arena growth in UsageHint kMetadata test. - #940
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Root Cause: VerifyUsageHintkMetadataTest installed a fresh region factory, allocated 2 GiB with operator new, and asserted that the last region created carried UsageHint::kMetadata. That relied on the pagemap growth for the new range (64 leaves, 2.6 MB) forcing the Arena back to the system allocator. The Arena can already hold that much: an aligned per-CPU slab allocation goes through SystemAllocator::Allocate with the slab alignment and the returned actual_size includes the alignment slop, which becomes free_avail_. Exercise the intended path directly: after SetRegionFactory, request bytes_unallocated + 1 from the Arena, which cannot be satisfied by the current free area or any freelist block and therefore must obtain a new region with UsageHint::kMetadata. Drop the 2 GiB user allocation, the leak suppression and the now unused leak_check dependency. Before: 8/3000 and 12/3000 failures. After: 3000/3000 pass. PiperOrigin-RevId: 982541454
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Force Arena growth in UsageHint kMetadata test.
Root Cause: VerifyUsageHintkMetadataTest installed a fresh region factory,
allocated 2 GiB with operator new, and asserted that the last region created
carried UsageHint::kMetadata. That relied on the pagemap growth for the new
range (64 leaves, 2.6 MB) forcing the Arena back to the system allocator. The
Arena can already hold that much: an aligned per-CPU slab allocation goes
through SystemAllocator::Allocate with the slab alignment and the returned
actual_size includes the alignment slop, which becomes free_avail_.
Exercise the intended path directly: after SetRegionFactory, request
bytes_unallocated + 1 from the Arena, which cannot be satisfied by the current
free area or any freelist block and therefore must obtain a new region with
UsageHint::kMetadata. Drop the 2 GiB user allocation, the leak suppression and
the now unused leak_check dependency.
Before: 8/3000 and 12/3000 failures. After: 3000/3000 pass.