c03a63d68d
Properly set/clear CHUNK_MAP_ZEROED for all purged pages, according to whether the pages are (potentially) file-backed or anonymous. This was merely a performance pessimization for the anonymous mapping case, but was a calloc()-related bug for the swap_enabled case.
jemalloc is a general-purpose scalable concurrent malloc(3) implementation. The INSTALL file contains information on how to configure, build, and install jemalloc.