Bug #17510
closedenable constant cache on Ractors
Description
constant cache IC
is accessed by non-atomic manner and there are
thread-safety issues, so Ruby 3.0 disables to use const cache on
non-main ractors.
To enable the constant cache, we need to make IC
access atomically,
and this is a patch: https://github.com/ruby/ruby/pull/4022
This patch enables it by introducing imemo_constcache and allocates
it by every re-fill of const cache like imemo_callcache.
Benchmark:
Warning[:experimental] = false
def tarai(x, y, z) = Object && # useless constant reference
x <= y ? y : tarai(tarai(x-1, y, z),
tarai(y-1, z, x),
tarai(z-1, x, y))
def task = tarai(12, 6, 0)
#
require 'benchmark'
Benchmark.bm{|x|
x.report('seq'){ 4.times{ task } }
x.report('par'){ 4.times.map{ Ractor.new{ task } }.each(&:take) }
}
master (095972e799):
user system total real
seq 1.618664 0.001916 1.620580 ( 1.620620)
par 18.168252 16.840400 35.008652 ( 9.452195)
This patch:
user system total real
seq 1.587542 0.000000 1.587542 ( 1.587548)
par 1.950062 0.000000 1.950062 ( 0.497173)
Updated by ko1 (Koichi Sasada) over 3 years ago
- Status changed from Open to Closed
Applied in changeset git|e7fc353f044f9280222ca41b029b1368d2bf2fe3.
enable constant cache on ractors
constant cache IC
is accessed by non-atomic manner and there are
thread-safety issues, so Ruby 3.0 disables to use const cache on
non-main ractors.
This patch enables it by introducing imemo_constcache
and allocates
it by every re-fill of const cache like imemo_callcache
.
[Bug #17510]
Now IC
only has one entry IC::entry
and it points to
iseq_inline_constant_cache_entry
, managed by T_IMEMO object.
IC
is atomic data structure so rb_mjit_before_vm_ic_update()
and
rb_mjit_after_vm_ic_update()
is not needed.
Updated by ko1 (Koichi Sasada) over 3 years ago
- Backport changed from 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN to 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: REQUIRED
this patch is for performance, but it seems be valuable to backport to 3.0.1.
Updated by k0kubun (Takashi Kokubun) over 3 years ago
e7fc353f04 broke MJIT, so if it's to be backported to 3.0.1, please make sure (87c546b5fa to avoid a conflict and) 7a3322a0fd is backported as well.
Updated by naruse (Yui NARUSE) over 3 years ago
- Backport changed from 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: REQUIRED to 2.5: DONTNEED, 2.6: DONTNEED, 2.7: DONTNEED, 3.0: REQUIRED
Updated by naruse (Yui NARUSE) over 3 years ago
- Backport changed from 2.5: DONTNEED, 2.6: DONTNEED, 2.7: DONTNEED, 3.0: REQUIRED to 2.5: DONTNEED, 2.6: DONTNEED, 2.7: DONTNEED, 3.0: DONE
ruby_3_0 b93e16dc0f45069d4a5fcce20d5c4437e151f0a8.