Details
-
Bug
-
Status: Resolved
-
Blocker
-
Resolution: Fixed
-
Impala 2.7.0
Description
When running the scanner fuzzing, I hit this DCHECK in the mempool integrity check. The issue seems to be connected with making large allocations. Looking at the code, I think there are at least two separate issues that could lead to this being hit with ReturnPartialAllocation() and in FindChunk() if the memory can't be allocated.
bool MemPool::CheckIntegrity(bool current_chunk_empty) {
DCHECK_EQ(zero_length_region_, MEM_POOL_POISON);
// Without pooling, there are way too many chunks and this takes too long.
if (FLAGS_disable_mem_pools) return true;
// check that current_chunk_idx_ points to the last chunk with allocated data
DCHECK_LT(current_chunk_idx_, static_cast<int>(chunks_.size()));
int64_t total_allocated = 0;
for (int i = 0; i < chunks_.size(); ++i) {
DCHECK_GT(chunks_[i].size, 0);
if (i < current_chunk_idx_) {
DCHECK_GT(chunks_[i].allocated_bytes, 0); <=== HERE
} else if (i == current_chunk_idx_) {
if (current_chunk_empty) {
DCHECK_EQ(chunks_[i].allocated_bytes, 0);
} else {
DCHECK_GT(chunks_[i].allocated_bytes, 0);
}
} else {
DCHECK_EQ(chunks_[i].allocated_bytes, 0);
}
total_allocated += chunks_[i].allocated_bytes;
}
DCHECK_EQ(total_allocated, total_allocated_bytes_);
return true;
}