[#45426] [ruby-trunk - Feature #6546][Open] Net::HTTP to check for HTTP_PROXY environment setting. — "dekz (Jacob Evans)" <dekzter@...>

14 messages 2012/06/04

[#45431] [ruby-trunk - Bug #6548][Open] Rake doesn't ignore arguments after -- — "rosenfeld (Rodrigo Rosenfeld Rosas)" <rr.rosas@...>

12 messages 2012/06/05

[#45474] [ANN] Request for "slide-show" of your feature proposal — Yusuke Endoh <mame@...>

(Japanese later; 日本語が後にあります)

18 messages 2012/06/07

[#45563] [ruby-trunk - Bug #6573][Open] Webrick test failures — "bkabrda (Bohuslav Kabrda)" <bkabrda@...>

19 messages 2012/06/11

[#45567] [ruby-trunk - Bug #6575][Open] Thread#kill sets rb_errinfo() to Fixnum 8 after rb_protect(function, data, &error_tag) — ibc (Iñaki Baz Castillo) <ibc@...>

9 messages 2012/06/11

[#45647] [ruby-trunk - Bug #6592][Open] test_call_double(DL::TestDL) fails on ARM HardFP — "vo.x (Vit Ondruch)" <v.ondruch@...>

15 messages 2012/06/14

[#45657] [ruby-trunk - Feature #6594][Open] Integrated Functor — "trans (Thomas Sawyer)" <transfire@...>

20 messages 2012/06/15

[#45664] [ruby-trunk - Bug #6596][Open] New method for Arrays : Array#index — "robin850 (Robin Dupret)" <robin.dupret@...>

20 messages 2012/06/15

[#45694] [ruby-trunk - Feature #6602][Open] Tail call optimization: enable by default? — "ko1 (Koichi Sasada)" <redmine@...>

12 messages 2012/06/18

[#45715] [ruby-trunk - Feature #6609][Open] Toplevel as self extended module — "trans (Thomas Sawyer)" <transfire@...>

17 messages 2012/06/19

[#45732] [ruby-trunk - Bug #6614][Open] GC doesn't collect objects bound to (collectable) proc — "rogerdpack (Roger Pack)" <rogerpack2005@...>

9 messages 2012/06/20

[#45733] [ruby-trunk - Feature #6615][Open] Release GVL in zlib when calling inflate() or deflate() — "drbrain (Eric Hodel)" <[email protected]>

12 messages 2012/06/21

[#45735] [ruby-trunk - Bug #6616][Open] MinGW: cannot build extensions or run tests due changes in exec_arg? — "luislavena (Luis Lavena)" <luislavena@...>

9 messages 2012/06/21

[#45798] [ruby-trunk - Bug #6634][Open] Deadlock with join and ConditionVariable — "meh. (meh. I don't care)" <meh@...>

20 messages 2012/06/23

[#45805] [ruby-trunk - Feature #6636][Open] Enumerable#size — "marcandre (Marc-Andre Lafortune)" <ruby-core@...>

15 messages 2012/06/23

[#45864] [ruby-trunk - Bug #6647][Open] Exceptions raised in threads should be logged — "headius (Charles Nutter)" <headius@...>

71 messages 2012/06/25

[#45902] [ruby-trunk - Bug #6653][Open] 1.9.2/1.9.3 exhibit SEGV with many threads+tcp connections — "erikh (Erik Hollensbe)" <erik@...>

11 messages 2012/06/26

[#45960] [ruby-trunk - Feature #6669][Open] A method like Hash#map but returns hash — "yhara (Yutaka HARA)" <redmine@...>

18 messages 2012/06/29

[#45963] [ruby-trunk - Feature #6670][Open] str.chars.last should be possible — "yhara (Yutaka HARA)" <redmine@...>

36 messages 2012/06/29

[#46021] [ruby-trunk - Feature #6679][Open] Default Ruby source file encoding to utf-8 — "claytrump (Clay Trump)" <clay.trump@...>

21 messages 2012/06/30

[ruby-core:45789] [ruby-trunk - Bug #6629][Open] [PATCH] io.c: avoid rb_thread_wait_fd() if we may call rb_io_wait_readable()

From: "normalperson (Eric Wong)" <normalperson@...>
Date: 2012-06-23 03:04:36 UTC
List: ruby-core #45789
Issue #6629 has been reported by normalperson (Eric Wong).

----------------------------------------
Bug #6629: [PATCH] io.c: avoid rb_thread_wait_fd() if we may call rb_io_wait_readable()
https://bugs.ruby-lang.org/issues/6629

Author: normalperson (Eric Wong)
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 
ruby -v: ruby 2.0.0dev (2012-06-23 trunk 36192) [x86_64-linux]


Blindly calling rb_thread_wait_fd() is an extra, unnecessary
system call in some cases.  Since we already call
rb_io_wait_readable() when encountering EAGAIN, there is no
user-visible change in behavior and a small potential for
speedup by avoiding a system call (especially on regular
filesystem that should never return EAGAIN/EINTR).

This also helps avoid triggering a bugs on some buggy (ancient)
Linux kernels.  I encountered this issue[1] on a CentOS 5.7
machine running the 2.6.18-274.7.1.el5 kernel.  Upgrading to
the 2.6.18-308.8.2.el5 kernel fixes the issue.

This Linux kernel regression I encountered was introduced with
commit 786d7e1612f0b0adb6046f19b906609e4fe8b1ba (Jul 15 2007)
and fixed in
commit dd23aae4f5edf4e1dbd8f7f8013a754ba3253f48 (Sep 11 2007)
I've verified the dd23aae4f5edf4e1dbd8f7f8013a754ba3253f48
change is present in the 2.6.18-308.8.2.el5 (working) kernel
but not in the 2.6.18-274.7.1.el5 (broken) kernel.

I realize this is a 5 year-old (fixed) bug in Linux, but I also
believe Ruby is is wrong to call select()/ppoll() before
encountering EAGAIN.

[1] http://mid.gmane.org/[email protected]

Note: I left IO#sysread unchanged (with just a comment) since
removing rb_thread_wait_fd() there would change semantics
(as would handling EAGAIN explicitly).



-- 
http://bugs.ruby-lang.org/

In This Thread

Prev Next