[cgl_discussion] PoC concall 10/8/03 Minutes

Zhao, Forrest forrest.zhao at intel.com
Mon Oct 13 02:28:17 PDT 2003

Hi, Steven

I have some update information and thoughts for epoll + libevent. Hope it's helpful.

1 epoll() has almost the same program interface with poll(), but it has the great scalability. That is, the performance of epoll() will not decrease when the number of file descriptors increases. For the detailed performance comparison data, you can go to http://lse.sourceforge.net/epoll/.
2 libevent is a user space lib that provides a mechanism to execute a callback function when a specific event occurs on a file descriptor or after a timeout has been reached. Furthermore, libevent also support callbacks due to signals or regular timeouts.
Currently, libevent supports kqueue(2), select(2), poll(2) and epoll(4). It also has experimental support for real-time signals. Support for /dev/poll is planned. 
3 One drawback with libevent: libevent can't support SMP. That is, libevent almost has the same performance in SMP with being used in UP. It can't utilize multiple processors to enhance the performance. Maybe we need to add the SMP support to libevent in order to make it perfect:)
There is a paper discussing this SMP support in event-driven program: http://citeseer.nj.nec.com/zeldovich02concurrency.html


-----Original Message-----
From: cgl_discussion-bounces at lists.osdl.org [mailto:cgl_discussion-bounces at lists.osdl.org] On Behalf Of Steven Dake
Sent: 2003年10月9日 0:08
To: cgl_discussion at osdl.org
Subject: [cgl_discussion] PoC concall 10/8/03 Minutes

*** Call to participants: If you have use cases for TIPC, please send
them to Mika.

Julie @ Intel
Rusty @ Intel
Johannes @ Nokia
Steve @ MontaVista
Ge @ Sun
John @ OSDL
Mark @ OSDL

TOP 10 List
IPSec maintainer disappeared, userfriendlyness not great but depends on
user opinion, some bugs.

PKI CA has had no distro input so unknown if distros will support.  Try
to determine distro input.

POC Try to analyze epoll + libevent to determine if it meets the
requirements still top 10.

2.7 Kernel Features List
IPv6 MIBs targeting end of november for production quality + 3 months
kernel timing
Robust Mutexes Priority Inheritence end of november for production
quality + 3 months kernel timing

Status Quality
* uSDE available end of Octoboer
* TIPC two implementations two projects.  John might propose yes
  quality by December.  OSDL working on acceptability to the mainline
kernel tree.
  Production quality by December possible, but may not be kernel
* No distro input on message passing, no idea if December deadlines
possible.  Ronski patch contains "merge" of the ideas in the two message
passing trees.  Latest Ronski patch in-kernel memory filesystem.



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