Bug #17995
closedSlow down when mjit and Ractor are being used at same time
Description
When using --jit and Ractor at same time, benchmark would be slow down with recursion function such like Tarai function an Fibonacci function.
The slow down is confirmed under both gcc(linux) and mingw64(windows MSYS2).
Test environment:
Cpu:Ryzen9 5900HS@3.3Ghz 8core/16thread
Memory:32GB@3200Mhz
OS:Ubuntu 21.04/Windows 10
Because of this cpu has 8 physic core,the parallel thread number is set to 8
Slow down is also confirmed with using only ractor (without sequence running).
When runing 'par' before 'seq' and using --mjit,'seq' is more slower than runing 'seq' berfore 'par'
Tarai function
def tarai(x, y, z) =
x <= y ? y : tarai(tarai(x-1, y, z),
tarai(y-1, z, x),
tarai(z-1, x, y))
require 'benchmark'
Benchmark.bm do |x|
# sequential version
x.report('seq'){ 8.times{ tarai(14, 7, 0) } }
# parallel version
x.report('par'){
8.times.map do
Ractor.new { tarai(14, 7, 0) }
end.each(&:take)
}
end
Fibonacci function
def fib(n)
if n==1 then return 1 end
if n==2 then return 1 end
fib(n-1)+fib(n-2)
end
require 'benchmark'
Benchmark.bm do |x|
# sequential version
x.report('fib:seq'){ 8.times{ fib(40) } }
# parallel version
x.report('fib:par '){
8.times.map do
Ractor.new {fib(40) }
end.each(&:take)
}
end
Updated by k0kubun (Takashi Kokubun) over 2 years ago
- Assignee set to k0kubun (Takashi Kokubun)
Updated by k0kubun (Takashi Kokubun) over 1 year ago
- Status changed from Open to Closed
Closing this since I replaced the implementation in [Feature #19420]. It doesn't mean that it works well with Ractor, but the current issue with Ractor should be reported separately since it's a completely different symptom.