From: "Eregon (Benoit Daloze)" Date: 2021-11-27T19:52:57+00:00 Subject: [ruby-core:106299] [Ruby master Feature#18364] Add GC.stat_size_pool for Variable Width Allocation Issue #18364 has been updated by Eregon (Benoit Daloze). I would avoid extending `GC.stat`, I think it is good it only contains `Symbols` to `Integer`, and there is probably code relying on that. Also `GC.stat(key)` seems relatively performance-sensitive as it's used in Rails for every request. I think a new method is good. Maybe GC.heap_stats/pool_stats/stat_pool` or so? I think it would be useful if this new method when given no arguments return a Hash of all heaps/memory pools, so it also serves as an easy way to list heaps/memory pools. And with an argument, only the stats for that specific heap/memory pool, and with 2 arguments the given stat for that memory pool. That way, whether a heap/memory pool is identified by a size or a name it would work in both cases. ---------------------------------------- Feature #18364: Add GC.stat_size_pool for Variable Width Allocation https://bugs.ruby-lang.org/issues/18364#change-94925 * Author: peterzhu2118 (Peter Zhu) * Status: Open * Priority: Normal * Assignee: matz (Yukihiro Matsumoto) ---------------------------------------- # GitHub PR: https://github.com/ruby/ruby/pull/5177 We're proposing an API to get statistics for size pools for Variable Width Allocation similar to `GC.stat`. This will make it easier for us (and other developers) to tune VWA. Before 3.1 release, we plan to keep this method hidden from the documentation using `:nodoc:` since it is not useful when not using VWA. For example: ```ruby # Get stats for size pool 2 puts GC.stat_size_pool(2) #=> {:slot_size=>160, :heap_allocatable_pages=>80, :heap_eden_pages=>14, :heap_eden_slots=>1424, :heap_tomb_pages=>0, :heap_tomb_slots=>0} puts GC.stat_size_pool(2, :heap_eden_pages) #=> 14 ``` We aim to keep the keys in the outputted hash the same as the keys used in `GC.stat`. We chose to implement a new method instead of re-using an existing API (`GC.stat`) because the keys returned by `GC.stat_size_pool` will not be the same as `GC.stat`. We believe that having `GC.stat` return different shapes of hashes based on its arguments is confusing. -- https://bugs.ruby-lang.org/ Unsubscribe: