From: alexandre@...
Date: 2014-07-11T22:31:08+00:00
Subject: [ruby-core:63670] [ruby-trunk - Bug #10009] IO operation is 10x slower in multi-thread environment

Issue #10009 has been updated by Alexandre Riveira.


Alexandre Riveira wrote:
> Eric Wong wrote:
> > 
> > Lowering TIME_QUANTUM_USEC (in thread_pthread.c) helps with the I/O case
> > (try it yourself if you have a 1000HZ kernel); but hurts overall
> > throughput.
> 
> Hello Eric!!!!
> 
> I stayed enjoyed the result of change TIME_QUANTUM_USEC. Changed its value to 1000

Tests completes, my system without changes join stress tests 30 secons for load page, after changes, pages loading in instant all pages loading in less than 1 second. 




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Bug #10009: IO operation is 10x slower in multi-thread environment
https://bugs.ruby-lang.org/issues/10009#change-47724

* Author: Alexandre Riveira
* Status: Open
* Priority: Urgent
* Assignee: 
* Category: 
* Target version: 
* ruby -v: ruby 2.1 x ruby 1.9.2 with taskset
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
I created this issue #9832 but not have io operation.
In the script attached I simulate IO operation in multi-thread environment.
For ruby 1.9.2 apply `taskset -c -p 2 #{Process.pid}` for regulates threads behavior.
The second Thread is a io operation

My results:

1) ruby 2.1.2
first 43500194
second 95
third 42184385

2) ruby-2.0.0-p451
first 38418401
second 95
third 37444470

3) 1.9.3-p545
first 121260313
second 50
third 44275164

4) 1.9.2-p320
first 31189901
second 897 <============
third 31190598

Regards


Alexandre Riveira


---Files--------------------------------
teste_thread_schedule_2.rb (1.05 KB)
teste_thread_schedule.py (953 Bytes)
teste_thread_schedule.rb (955 Bytes)
test_thread_sched_pipe.rb (1.01 KB)


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