| Summary: | ASTERISK-12328: [patch] find_idle_thread() uses spin wait | ||
| Reporter: | Peter Grayson (jpgrayson) | Labels: | |
| Date Opened: | 2008-07-07 14:01:59 | Date Closed: | 2008-11-04 16:52:04.000-0600 |
| Priority: | Minor | Regression? | No |
| Status: | Closed/Complete | Components: | Channels/chan_iax2 |
| Versions: | Frequency of Occurrence | ||
| Related Issues: | |||
| Environment: | Attachments: | ( 0) chan_iax2_find_idle.patch | |
| Description: | When find_idle_thread() creates a new dynamic thread, it spins waiting for the newly created thread to "signal" that it is up, running, and ready to go. On a lightly loaded system, the child thread will be scheduled promptly and the parent thread will thus probably not spin too much. On a heavily loaded system, it might be possible for the parent thread to be rescheduled many times prior to the child thread becoming ready. This is a waste of CPU when the system can least afford it. Instead of spin waiting, a condition variable can be used. This would make the parent thread efficiently block until the child thread becomes ready. | ||
| Comments: | By: Peter Grayson (jpgrayson) 2008-07-07 14:11:33 The attached patch replaces the find_idle_thread() spin wait with a condition variable. Note that this also removes the odd-ball use of bitfield with the ready_for_signal variable. By: Russell Bryant (russell) 2008-10-06 08:46:13 The patch looks good. Someone just needs to update it to trunk and then it can be applied. By: Digium Subversion (svnbot) 2008-11-04 16:52:02.000-0600 Repository: asterisk Revision: 154428 U trunk/channels/chan_iax2.c ------------------------------------------------------------------------ r154428 | tilghman | 2008-11-04 16:52:02 -0600 (Tue, 04 Nov 2008) | 7 lines Switch to using a thread condition to signal that a child thread is ready for work, rather than a busy wait. (closes issue ASTERISK-12328) Reported by: jpgrayson Patches: chan_iax2_find_idle.patch uploaded by jpgrayson (license 492) ------------------------------------------------------------------------ http://svn.digium.com/view/asterisk?view=rev&revision=154428 | ||