Ruby gvl-improvement at ruby 1.9.3

Ruby 1.9.3 GVL FujitsuSunday, July 17, 2011

Who am I?Sunday, July 17, 2011

• • IO OS • usaSunday, July 17, 2011

at Linux Kernel Summit 2010Sunday, July 17, 2011

Shyouhei commiter ranking me!Sunday, July 17, 2011

Sunday, July 17, 2011

GVLSunday, July 17, 2011

What’s GVL • Global(or Giant) VM Lock • • multi thread issue Ruby script • CPU • PythonSunday, July 17, 2011

What’s GVL (cont.) • GVL • GVL • OSSunday, July 17, 2011

f = false Thread.new { ....; f = true } Thread.pass until fSunday, July 17, 2011

GVL design • Lock wait (e.g. write) • lock, unlock Python, QEMU, Linux • GVL acquire/release pthread_mutex_{lock,unlock}Sunday, July 17, 2011

GVL design (cont.) • •Sunday, July 17, 2011

GVL design (cont.) • ON if (th->interrupt_ﬂag) { gvl_release(); sched_yield(); gvl_acquire(); }Sunday, July 17, 2011

• OSS while (true) { ( ) lock(); if (hoge) { unlock(); break; • } unlock(); • thread lock rep_nop(); } hoge=1 lock(); hoge = 1; unlock();Sunday, July 17, 2011

Why?Sunday, July 17, 2011

CPU cpu1 cpu2 memory core core core core memory 1 2 core core core coreSunday, July 17, 2011

if (th->interrupt_ﬂag) { gvl_release(); sched_yield(); gvl_acquire(); } •gvl_release() gvl_acquire() sched_yield() • sched_yield() yieldSunday, July 17, 2011

sched_yield • Unix API http://pubs.opengroup.org/onlinepubs/009695399/ functions/sched_yield.html int sched_yield(void); • The sched_yield() function shall force the running thread to relinquish the processor until it again becomes the head of its thread list. •Sunday, July 17, 2011

Thread core Thread Thread Thread Thread core Thread coreSunday, July 17, 2011

(ry CPU Thread core Thread Thread Thread core Thread Thread core ThreadSunday, July 17, 2011

Yield! Ruby Thread core Thread Thread core Ruby ThreadSunday, July 17, 2011

thread list head Thread core Ruby Thread Thread core Ruby ThreadSunday, July 17, 2011

Ruby Thread core Thread Thread core Ruby Thread POSIXSunday, July 17, 2011

CFS yield • Linux RHEL5 RHEL6 • RHEL6 (CFS) sched_yield (RHEL5 knob • Java • Linux upstream knob CPUSunday, July 17, 2011

• fairnessSunday, July 17, 2011

• fairness • GVL gvl_acquire gvl_release mutex_lock(&lock->lock) mutex_lock(&lock->lock) cond_wait(&lock->wait) lock->acquired = 0; lock->acquired = 1; cond_signal(&lock->wait_cond) // // cond_signal(&lock->switch_cond) cond_wait(&lock->switch_cond) mutex_unlock(&lock->lock) mutex_unlock(&lock->lock)Sunday, July 17, 2011

vm_thread_pipe lmax = 100_000 r, w = IO.pipe [Thread.new{ lmax.times{ w.write(a) } p "w:exit" }, Thread.new{ lmax.times{ r.read(1) } p "r:exit" }].each{|t| t.join}Sunday, July 17, 2011

(´ ω )Sunday, July 17, 2011

• fairness • unfairness • Linux •Sunday, July 17, 2011

1.9.3 • 1.9.3 IO GVL release GVL release • IO GVL 1.9.2 IO GVL switch • GVL release switch GVL •Sunday, July 17, 2011

1.9.2 1.9.3 2 1.5 1 0.5 0 create_join mutex1 mutex2 mutex3 pass_flood pipeSunday, July 17, 2011

• 1.9.2 • • •Sunday, July 17, 2011

vm_thread_mutex3Sunday, July 17, 2011

Sunday, July 17, 2011

• CPU • GVL CPU • RubySunday, July 17, 2011

Question?Sunday, July 17, 2011

http://mkosaki.blog46.fc2.com	3977
http://www.slideshare.net	8
http://twitter.com	4
https://twitter.com	1
http://s.deeeki.com	1
http://paper.li	1

Ruby gvl-improvement at ruby 1.9.3

by Motohiro Kosaki on Jul 17, 2011

Accessibility

Categories

Tags

Upload Details

Usage Rights

6 Embeds 3,992

Statistics

Ruby gvl-improvement at ruby 1.9.3 — Presentation Transcript