diff options
| -rw-r--r-- | runtime/gc/space/region_space.cc | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/runtime/gc/space/region_space.cc b/runtime/gc/space/region_space.cc index 76816ddd2e..60141d656b 100644 --- a/runtime/gc/space/region_space.cc +++ b/runtime/gc/space/region_space.cc @@ -741,10 +741,19 @@ bool RegionSpace::LogFragmentationAllocFailure(std::ostream& os, max_contiguous_allocation = std::min(max_contiguous_allocation, regions_free_for_alloc * kRegionSize); if (failed_alloc_bytes > max_contiguous_allocation) { + // Region space does not normally fragment in the conventional sense. However we can run out + // of region space prematurely if we have many threads, each with a partially committed TLAB. + // The whole TLAB uses up region address space, but we only count the section that was + // actually given to the thread so far as allocated. For unlikely allocation request sequences + // involving largish objects that don't qualify for large objects space, we may also be unable + // to fully utilize entire TLABs, and thus generate enough actual fragmentation to get + // here. This appears less likely, since we usually reuse sufficiently large TLAB "tails" + // that are no longer needed. os << "; failed due to fragmentation (largest possible contiguous allocation " - << max_contiguous_allocation << " bytes). Number of " - << PrettySize(kRegionSize) - << " sized free regions are: " << regions_free_for_alloc; + << max_contiguous_allocation << " bytes). Number of " << PrettySize(kRegionSize) + << " sized free regions are: " << regions_free_for_alloc + << ". Likely cause: (1) Too much memory in use, and " + << "(2) many threads or many larger objects of the wrong kind"; return true; } // Caller's job to print failed_alloc_bytes. |