Issue #20145 has been reported by peterzhu2118 (Peter Zhu). ---------------------------------------- Bug #20145: Memory leak when duplicating identhash https://bugs.ruby-lang.org/issues/20145 * Author: peterzhu2118 (Peter Zhu) * Status: Open * Priority: Normal * Backport: 3.0: UNKNOWN, 3.1: REQUIRED, 3.2: REQUIRED, 3.3: REQUIRED ---------------------------------------- GitHub PR: https://github.com/ruby/ruby/pull/9411 Both copy_compare_by_id and hash_copy will create a copy of the ST table, so the ST table created in copy_compare_by_id will be leaked. ```ruby h = { 1 => 2 }.compare_by_identity 10.times do 1_000_000.times do h.select { false } end puts `ps -o rss= -p #{$$}` end ``` Before: ``` 110736 204352 300272 395520 460704 476736 542000 604704 682624 770528 ``` After: ``` 15504 16048 16144 16256 16320 16320 16752 16752 16752 16752 ``` -- https://bugs.ruby-lang.org/