Backport #2277: Patch: Fix high CPU usage on Kernel#select

• Status: Closed
• Assignee: nobu (Nobuyoshi Nakada)

[zakaria (Zakaria Haris)]

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This bug brought my server down two times.
While my patch for p111 it still exist in p287.

diff -ru ruby-1.8.6-p111.orig/io.c ruby-1.8.6-p111/io.c
--- ruby-1.8.6-p111.orig/io.c Tue May 22 23:28:10 2007
+++ ruby-1.8.6-p111/io.c Sun Aug 30 19:08:09 2009
@@ -4802,12 +4802,12 @@
if (!pending && n == 0) return Qnil; /* returns nil on timeout */

  res = rb_ary_new2(3);

• rb_ary_push(res, rp?rb_ary_new():rb_ary_new2(0));

• rb_ary_push(res, (rp||pending)?rb_ary_new():rb_ary_new2(0));
  rb_ary_push(res, wp?rb_ary_new():rb_ary_new2(0));
  rb_ary_push(res, ep?rb_ary_new():rb_ary_new2(0));

  if (interrupt_flag == 0) {

• if (rp) {

• if (rp || pending) {
  list = RARRAY(res)->ptr[0];
  for (i=0; i< RARRAY(read)->len; i++) {
  GetOpenFile(rb_io_get_io(RARRAY(read)->ptr[i]), fptr);
  =end

[nobu (Nobuyoshi Nakada)]

=begin
Hi,

At Mon, 26 Oct 2009 22:55:47 +0900,
Zakaria Haris wrote in [ruby-core:26323]:

 res = rb_ary_new2(3);

• rb_ary_push(res, rp?rb_ary_new():rb_ary_new2(0));

• rb_ary_push(res, (rp||pending)?rb_ary_new():rb_ary_new2(0));

Seems curious. When pending is non-zero, rp should be always
set.

--
Nobu Nakada

=end

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Feedback

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=end

[ujihisa (Tatsuhiro Ujihisa)]

• Assignee set to nobu (Nobuyoshi Nakada)

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=end

[rogerdpack (Roger Pack)]

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do you have an example of how to reproduce this?
=end

[jeremyevans0 (Jeremy Evans)]

• Tracker changed from Bug to Backport
• Project changed from Ruby 1.8 to Backport187
• Description updated (diff)
• Status changed from Feedback to Closed
• ruby -v deleted (1.8.6)