From: lourens@... Date: 2019-10-07T22:52:48+00:00 Subject: [ruby-core:95272] [Ruby master Feature#16245] Add interfaces to count and measure size all IMEMO objects Issue #16245 has been updated by methodmissing (Lourens Naud�). sam.saffron (Sam Saffron) wrote: > Koichi introduced an experimental gem: https://github.com/ko1/iseq_collector > > It allows: > > ObjectSpace.each_iseq{|iseq| ...} > ObjectSpace.count_iseq #=> Integer > ObjectSpace.memsize_of_all_iseq (should not generate RubyVM::InstructionSequence wrappers for IMEMOs) > > Since the wrapper object RubyVM::InstructionSequence is lazily allocated, ObjectSpace.each_object does not find these IMEMOs unless they have been wrapped. This design is good and conserves memory. > > `count_iseq` and `memsize_of_all_iseq` are very powerful metrics most large Ruby deployments can use to automatically detect method leaks introduced via meta programming. These issues are invisible now short of walking a heap dump. > > Can we add the new interface into 2.7? I worked on `imemo_memsize` some time ago to correctly reflect the type sizes in https://github.com/ruby/ruby/commit/90c4bd2d2bd10b19c2b09834396553742bc7e8a4 which makes heap dumps more accurate. I understand the API proposal, but also I believe the intention was for these objects to be internal and not necessarily to be exposed through API. However I do suspect for large Rails applications their combined footprint can add up, especially for the types that can allocate heap memory too: * imemo_ment (method entries) * imemo_iseq (as per your description above) * imemo_env (bindings) * imemo_tmpbuf (tried to support these on the transient heap but found them to be almost never used much in practice as it appears to be a fallback for `ALLOCA` under some circumstances. * imemo_ast I have not had any free time to investigate further, but I think this is an interesting storage class to explore further and I'd be interesting in helping, whichever way the proposal goes. ---------------------------------------- Feature #16245: Add interfaces to count and measure size all IMEMO objects https://bugs.ruby-lang.org/issues/16245#change-81948 * Author: sam.saffron (Sam Saffron) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- Koichi introduced an experimental gem: https://github.com/ko1/iseq_collector It allows: ObjectSpace.each_iseq{|iseq| ...} ObjectSpace.count_iseq #=> Integer ObjectSpace.memsize_of_all_iseq (should not generate RubyVM::InstructionSequence wrappers for IMEMOs) Since the wrapper object RubyVM::InstructionSequence is lazily allocated, ObjectSpace.each_object does not find these IMEMOs unless they have been wrapped. This design is good and conserves memory. `count_iseq` and `memsize_of_all_iseq` are very powerful metrics most large Ruby deployments can use to automatically detect method leaks introduced via meta programming. These issues are invisible now short of walking a heap dump. Can we add the new interface into 2.7? -- https://bugs.ruby-lang.org/ Unsubscribe: