End of Life Ruby 3.2 has reached end of life and gets no more fixes. Switch to Ruby 4.0 →

class method

GC.auto_compact=

GC.auto_compact = flag

static VALUE
gc_set_auto_compact(VALUE _, VALUE v)
{
    GC_ASSERT(GC_COMPACTION_SUPPORTED);

    ruby_enable_autocompact = RTEST(v);
    return v;
}

Updates automatic compaction mode.

When enabled, the compactor will execute on every major collection.

Enabling compaction will degrade performance on major collections.

Ruby version changes

3.0
- GC.auto_compact= and GC.auto_compact have been added to control when compaction runs. Setting auto_compact= to true will cause compaction to occur during major collections. At the moment, compaction adds significant overhead to major collections, so please test first! [Feature #17176]

See also .auto_compact .compact .add_stress_to_class .count also in 4.1 · 3.3 · 3.1 · 3.0