From: Eric Wong <normalperson@yhbt.net>
To: ruby-core@ruby-lang.org
Subject: [ruby-core:81078] Re: [ruby-cvs:65407] normal:r58236 (trunk): thread.c: comments on M:N threading [ci skip]
Date: Tue, 9 May 2017 18:51:40 +0000 [thread overview]
Message-ID: <20170509185140.GA17410@starla> (raw)
In-Reply-To: <f85296f3-0fc6-7e4a-2548-b356cf9fbd49@atdot.net>
SASADA Koichi <ko1@atdot.net> wrote:
> On 2017/05/09 15:23, Eric Wong wrote:
> > OK. I also started to work on making GVL switch nd remaining native
> > mutex/condvars faster on Linux by using futex. However, it is only
> > faster with multi-core, single core performance is a little slower.
> >
> > https://80x24.org/spew/20170509062022.4413-1-e@80x24.org/raw
> > (I still use my Pentium-M laptop from 2005 :)
>
> Let us clear the your plan.
>
> Maybe we have several tasks.
>
> (1) lightweight fiber switching by pointer-exchange
> (w/o copying context).
Out of all tasks here, I am least familiar with this (1).
This will be learning experience for me.
> (2) auto-fiber swiching
> (2-1) implement with epoll/kqueue/select
> (2-2) design APIs to use it
I think I will start on the select implementation first for
portability, but model our internal API around epoll(*).
I will probably implement epoll support last, since I am
most familiar with it.
(*) with current GVL, I expect our kqueue+kevent implementation
will be faster than epoll in most cases (the API requires
fewer syscalls). select might be fastest with few FDs.
> (3) Implement GVL with futex (in your comment)
Maybe last. Linux-only, single (but most important)
platform; and the single CPU regression needs to be fixed.
> (4) Re-implement Queue (some days ago you wrote)
I already had some work-in-progress patches I can cleanup and
send out to redmine for review later (also ConditionVariable).
Last I remember, there was a small performance regression for
small Queue/Condvar waiter lists due to better locality on embed
structs. However, I think avoiding O(n) rb_ary_delete behavior
is more important for busy queues.
> (please add your plan if you have others)
I might break out thread.c and io.c into smaller files
(select/epoll/kqueue/timer_thread/copy_stream/...)
to make code organization easier.
> Do you have a schedule? (priority?)
I don't know how long (1) will take, (4) is almost done.
(2) maybe 1-3 weeks. (3) not sure how long it will take
to fix single CPU performance.
Also, I will try not to break platforms I don't use. As you
know I only use Free Software, so I would appreciate if you or
platform maintainers can help fix portability bugs on non-Free
systems.
Do you have any deadlines or priorities?
next prev parent reply other threads:[~2017-05-09 18:08 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20170402011414.AEA9B64CEE@svn.ruby-lang.org>
[not found] ` <8a2b82e3-dc07-1945-55f9-5a474e89130b@ruby-lang.org>
2017-04-02 2:35 ` [ruby-core:80531] Re: [ruby-cvs:65407] normal:r58236 (trunk): thread.c: comments on M:N threading [ci skip] Eric Wong
2017-04-02 3:05 ` [ruby-core:80532] " SASADA Koichi
2017-04-03 4:42 ` [ruby-core:80540] " Eric Wong
2017-05-08 0:33 ` [ruby-core:81027] " Eric Wong
2017-05-08 1:53 ` [ruby-core:81028] " SASADA Koichi
2017-05-08 2:16 ` [ruby-core:81029] " SASADA Koichi
2017-05-08 3:01 ` [ruby-core:81031] " Eric Wong
2017-05-08 3:42 ` [ruby-core:81033] " SASADA Koichi
2017-05-08 6:36 ` [ruby-core:81035] " Eric Wong
2017-05-09 2:18 ` [ruby-core:81042] " SASADA Koichi
2017-05-09 3:38 ` [ruby-core:81044] " Eric Wong
2017-05-09 4:11 ` [ruby-core:81045] " SASADA Koichi
2017-05-09 5:12 ` [ruby-core:81047] " Eric Wong
2017-05-09 5:47 ` [ruby-core:81049] " SASADA Koichi
2017-05-09 6:23 ` [ruby-core:81053] " Eric Wong
2017-05-09 6:44 ` [ruby-core:81054] " SASADA Koichi
2017-05-09 18:51 ` Eric Wong [this message]
2017-05-10 3:24 ` [ruby-core:81083] " SASADA Koichi
2017-05-10 10:04 ` [ruby-core:81089] " Eric Wong
2017-05-19 4:34 ` [ruby-core:81244] " Eric Wong
2017-06-20 19:16 ` [ruby-core:81733] " Eric Wong
2017-05-09 5:54 ` [ruby-core:81050] " SASADA Koichi
2017-05-09 6:15 ` [ruby-core:81052] " Eric Wong
2017-05-08 2:56 ` [ruby-core:81030] " Eric Wong
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