Forum: Ruby-core [Open] minor iseq memory reductions

18813f71506ebad74179bf8c5a136696?d=identicon&s=25 unknown (Guest)
on 2014-08-30 03:42
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Issue #10187 has been reported by Eric Wong.

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Feature #10187: minor iseq memory reductions
https://bugs.ruby-lang.org/issues/10187

* Author: Eric Wong
* Status: Open
* Priority: Low
* Assignee: Eric Wong
* Category: core
* Target version: current: 2.2.0
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Pretty trivial and low impact, but I figure we might as well reduce
memory footprint a few kilobytes where we can and let the reductions
accumulate.  Feature #10185 has much bigger impact.

* [PATCH 1/2] iseq_inline_storage_entry: 24=>16 bytes on x86-64

We may tag the running_thread pointer to avoid making the "once" struct
bigger than "struct iseq_inline_cache_entry".

This only saves a small amount with "valgrind ruby -e exit"
before:
  total heap usage: 48,122 allocs, 19,248 frees, 8,110,149 bytes
allocated
after:
  total heap usage: 48,122 allocs, 19,253 frees, 8,099,197 bytes
allocated

* [PATCH 2/2] rb_call_info_t: 104=>96 bytes on x86-64

This keeps ci->flag and ci->aux.index consistent across 32-bit
and 64-bit platforms.

ci->flag: VM_CALL_* flags only use 9 bits, currently
ci->aux.index: 2 billion ivars per class should be enough for anybody

This saves around 50K allocations on "valgrind ruby -e exit"
before:
  total heap usage: 48,122 allocs, 19,253 frees, 8,099,197 bytes
allocated
after:
  total heap usage: 48,069 allocs, 19,214 frees, 8,047,266 bytes
allocated


---Files--------------------------------
inline_storage-16.patch (2.45 KB)
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