jemalloc To control how jemalloc handles freed memory MALLOC_CONF="narenas:2,dirty_decay_ms:1000,muzzy_decay_ms:1000,background_thread:true" To Confirm MALLOC_CONF Was Applied tr '\0' '\n' < /proc/$(pgrep -f sidekiq)/environ | grep MALLOC_CONF Check Which Libraries Ruby is Linked Against ruby -r rbconfig -e "puts RbConfig::CONFIG['MAINLIBS']" Elsewhere malloc doubles ruby memory