Re: [patch 00/13] Syslets, "Threadlets", generic AIO support, v3

[Ingo Molnar <mingo@elte.hu>]

* Evgeniy Polyakov <johnpol@2ka.mipt.ru> wrote:

> CPU: AMD64 processors, speed 2210.08 MHz (estimated)
> Counted CPU_CLK_UNHALTED events (Cycles outside of halt state) with a unit mask of 0x00 (No unit mask) count 100000
> samples  %        symbol name
> 195750   67.3097  cpu_idle
> 14111     4.8521  enter_idle
> 4979      1.7121  IRQ0x51_interrupt
> 4765      1.6385  tcp_v4_rcv

the pretty much only meaningful way to measure this is to:

- start a really long 'ab' testrun. Something like "ab -c 8000 -t 600".
- let the system get into 'steady state': i.e. CPU load at 100%
- reset the oprofile counters, then start an oprofile run for 60 
  seconds.
- stop the oprofile run.
- stop the test.

this way there wont be that many 'cpu_idle' entries in your profiles, 
and the profiles between the two event delivery mechanisms will be 
directly comparable.

> In that tests I got epoll perf about 4400 req/s, kevent was about 
> 5300.

So we are now up to epoll being 83% of kevent's performance - while the 
noise of numbers seen today alone is around 100% ... Could you update 
the files two URLs that you posted before, with the code that you used 
for the above numbers:

   http://tservice.net.ru/~s0mbre/archive/kevent/evserver_epoll.c
   http://tservice.net.ru/~s0mbre/archive/kevent/evserver_kevent.c

thanks,

	Ingo