----- Original Message ----- From: "Markus Storm" <markus.storm@xxxxxxxxxxxxx> Sent: Thursday, April 15, 2004 4:18 PM > Second, I encountered the same c10k discussion when I tried to tune a > Squid HTTP > proxy some (long) time ago. > More or less same problem there, thousands of connections need to be > proxied. > Squid uses select(), too, and the ratio # connection vs. needed cpupower > per connection > is even worse for HTTP compared to H.323/RTP, so the select() issue > should have an > even higher impact in that case. > I vaguely recall that the outcome was that "nowadays", select() is no > longer a bottleneck > because internal to many operating systems, it is implemented in a > different way, similar to poll(). > That was at least true for Solaris. I ain't sure about Linux, though. > Third, my figures just showed how cpu usage distributes over all syscalls. > I do also see, however, that about or close to half of the CPU is burned > in userspace > and the other half in sysspace. select() should be counted as sys usage, > right? You may try to use gigabit ethernet and approtiate linux kernel, so the network card does not generate an interrupt per each packet. I've been pointed to some interesting link on this: ftp://robur.slu.se/pub/Linux/net-development/NAPI/NAPI_HOWTO.txt > So while we may or may not be hit by c10k select() CPU burner, still > half of the CPU is used by somebody else. > And as gnugk just needs to copy one RTP stream into another, the > corresponding code > is pretty simple and shouldn't use much CPU, so what's probably eating > CPU is the > openh323 lib. > I know this is absolutely half-hearted guessing and I should use a real > profiling program > to find out what it is really doing, but again, I'm no programmer. If you have gnugk compiled with large_fdset enabled, then pwlib sockets implementation is replaced with the lightweight one from gnugk. ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________________ List: Openh323gk-users@xxxxxxxxxxxxxxxxxxxxx Archive: http://sourceforge.net/mailarchive/forum.php?forum_id=8549 Homepage: http://www.gnugk.org/
