Issue #14718 has been updated by mame (Yusuke Endoh). Status changed from Open to Rejected jemalloc development has been discontinued. https://jasone.github.io/2025/06/12/jemalloc-postmortem/ ---------------------------------------- Feature #14718: Use jemalloc by default? https://bugs.ruby-lang.org/issues/14718#change-114362 * Author: mperham (Mike Perham) * Status: Rejected ---------------------------------------- I know Sam opened #9113 4 years ago to suggest this but I'm revisiting the topic to see if there's any movement here for Ruby 2.6 or 2.7. I supply a major piece of Ruby infrastructure (Sidekiq) and I keep hearing over and over how Ruby is terrible with memory, a huge memory hog with their Rails apps. My users switch to jemalloc and a miracle occurs: their memory usage drops massively. Some data points: https://twitter.com/brandonhilkert/status/987400365627801601 https://twitter.com/d_jones/status/989866391787335680 https://github.com/mperham/sidekiq/issues/3824#issuecomment-383072469 Redis moved to jemalloc many years ago and it solved all of their memory issues too. Their conclusion: the glibc allocator "sucks really really hard". http://oldblog.antirez.com/post/everything-about-redis-24.html This is a real pain point for the entire Rails community and would improve Ruby's reputation immensely if we can solve this problem. ---Files-------------------------------- glibc_arena_2.png (7.23 KB) jemalloc.png (21.1 KB) glibc-arena-2.log (60.3 KB) glibc.log (62.3 KB) jemalloc-3-5.log (58.5 KB) glibc.png (9.03 KB) -- https://bugs.ruby-lang.org/