Table 1. mallopt() Parameters Mapped to Environment

mallopt() option Env var Default value Notes
M_TRIM_THRESHOLD MALLOC_TRIM_THRESHOLD_ 128KB -1U disables
M_TOP_PAD MALLOC_TOP_PAD_ 0
M_MMAP_THRESHOLD MALLOC_MMAP_THRESHOLD_ 128KB 0 disables
M_MMAP_MAX MALLOC_MMAP_MAX_ 64 0 disables