Bug #19907: Method calls with keyword arguments in eval leaks callcache and callinfo objects

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 3.0: WONTFIX, 3.1: REQUIRED, 3.2: REQUIRED, 3.3: DONE

[peterzhu2118 (Peter Zhu)]

The following script leaks callcache and callinfo objects:

def foo(a:); end

10.times do
  10_000.times do
    eval(<<~RUBY)
      foo(a: 1)
    RUBY
  end

  puts "Number of live objects: #{GC.stat(:heap_live_slots)}"
  puts "Memory usage: #{`ps -o rss= -p #{$$}`}"
  puts
end

Output is:

Number of live objects: 46248
Memory usage:  16160

Number of live objects: 65902
Memory usage:  19888

Number of live objects: 92656
Memory usage:  24032

Number of live objects: 126791
Memory usage:  28048

Number of live objects: 132919
Memory usage:  28816

Number of live objects: 180687
Memory usage:  32384

Number of live objects: 181957
Memory usage:  32464

Number of live objects: 227485
Memory usage:  34224

Number of live objects: 256101
Memory usage:  37200

Number of live objects: 274151
Memory usage:  38752

After performing a ObjectSpace.dump_all, I found that it is leaking callcache and callinfo objects that is being held on by the Object class.

{"address":"0x102ecef70", "type":"CLASS", "shape_id":2, "slot_size":160, "class":"0x102ecf8d0", "variation_count":0, "superclass":"0x102ecfd30", "real_class_name":"Object", "singleton":true, "references":[ ... ]}
{"address":"0x1030c90a0", "type":"IMEMO", "shape_id":0, "slot_size":40, "imemo_type":"callinfo", "mid":"foo", "memsize":40, "flags":{"wb_protected":true}}
{"address":"0x102fad568", "type":"IMEMO", "shape_id":0, "slot_size":40, "imemo_type":"callcache", "memsize":40, "flags":{"wb_protected":true, "old":true, "uncollectible":true, "marked":true}}

[jeremyevans0 (Jeremy Evans)]

• Related to Bug #18553: Memory leak on compiling method call with kwargs added

[jhawthorn (John Hawthorn)]

• Related to Bug #19970: Eval leaks callcache and callinfo objects on arm32 (linux) added

[jhawthorn (John Hawthorn)]

https://github.com/ruby/ruby/pull/9973

I've opened a PR to de-dup identical callinfo, which will also in this case avoid the allocation of unnecessary callcache.

Running the script above:

Number of live objects: 9139
Memory usage: 19620

Number of live objects: 13132
Memory usage: 19620

Number of live objects: 12728
Memory usage: 19620

Number of live objects: 13451
Memory usage: 19620

Number of live objects: 10028
Memory usage: 19620

Number of live objects: 13150
Memory usage: 19620

Number of live objects: 12210
Memory usage: 19620

Number of live objects: 12538
Memory usage: 19620

Number of live objects: 9023
Memory usage: 19620

Number of live objects: 11948
Memory usage: 19620

[byroot (Jean Boussier)]

• Related to Bug #20348: Memory leak with method kwargs in ERB template added

[byroot (Jean Boussier)]

• Backport changed from 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN to 3.0: WONTFIX, 3.1: REQUIRED, 3.2: REQUIRED, 3.3: REQUIRED

[byroot (Jean Boussier)]

• Status changed from Open to Closed

Fixed by 1c97abaabae6844c861705fd07f532292dcffa74 and 081ee3d35509110f383cb7dd8d1205def0cdd1e8

[naruse (Yui NARUSE)]

• Backport changed from 3.0: WONTFIX, 3.1: REQUIRED, 3.2: REQUIRED, 3.3: REQUIRED to 3.0: WONTFIX, 3.1: REQUIRED, 3.2: REQUIRED, 3.3: DONE

ruby_3_3 57a0afe2090b8d05673d650b1e8bf9ae67449b1f merged revision(s) 081ee3d35509110f383cb7dd8d1205def0cdd1e8,1c97abaabae6844c861705fd07f532292dcffa74.