Bugzilla

Currently, our jemalloc implementation, during deallocation of memory <1 MB, acquires the arena lock used by all small- and large-block allocations, and then performs a `memset()` on the to-be-deallocated block of memory. If this block of memory is paged out, then the arena lock is held during the swap-in process, which blocks all other threads in the process from allocating memory blocks <1 MB.

During evaluation of IPC evaluation, it was found that allocation of blocks of memory in the 128 byte - 4096 byte range would occasionally take several hundred milliseconds. The locking behavior described above is the most likely suspect for why this delay might occur.

This bug is to track an experiment to examine the performance impact of attempts to alleviate the arena lock contention caused by the behavior described above.

Currently, our jemalloc implementation, during deallocation of memory <1 MB, acquires the arena lock used by all small- and large-block allocations, and then performs a `memset()` on the to-be-deallocated block of memory. If this block of memory is paged out, then the arena lock is held during the swap-in process, which blocks all other threads in the process from allocating memory blocks <1 MB.

During evaluation of IPC performance, it was found that allocation of blocks of memory in the 128 byte - 4096 byte range would occasionally take several hundred milliseconds. The locking behavior described above is the most likely suspect for why this delay might occur.

This bug is to track an experiment to examine the performance impact of attempts to alleviate the arena lock contention caused by the behavior described above.