From: fweimer@... Date: 2018-07-30T12:16:48+00:00 Subject: [ruby-core:88195] [Ruby trunk Feature#14718] Use jemalloc by default? Issue #14718 has been updated by fweimer (Florian Weimer). I can reproduce your MALLOC_ARENA_MAX=2 numbers, but my glibc 2.26 numbers are slightly worse (presumably due to the thread cache, which delays coalescing even further): ~~~ count 5000.000000 mean 2299.963311 std 589.499758 min 143.515625 25% 2120.331055 50% 2539.085938 75% 2728.136719 max 2887.113281 ~~~ With jemalloc 4.5, I get very similar numbers to glibc 2.26: ~~~ count 5000.000000 mean 2137.653509 std 397.754364 min 178.406250 25% 2053.171875 50% 2148.148438 75% 2347.949219 max 2571.218750 ~~~ jemalloc 5.0.1 may be slightly better, but it is not a large change: ~~~ count 5000.000000 mean 1844.086273 std 338.717582 min 176.300781 25% 1848.468750 50% 1935.281250 75% 2011.210938 max 2158.937500 ~~~ jemalloc 5.1 is slightly worse, it seems. ~~~ count 5000.000000 mean 2027.594097 std 365.946724 min 176.437500 25% 1967.921875 50% 2073.148438 75% 2245.913086 max 2508.105469 ~~~ Based on these tests, untuned current jemalloc shows only a very moderate improvement over untuned glibc. ---------------------------------------- Feature #14718: Use jemalloc by default? https://bugs.ruby-lang.org/issues/14718#change-73214 * Author: mperham (Mike Perham) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- 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/ Unsubscribe: