On Thu, Mar 01, 2007 at 10:54:02AM +0100, Ingo Molnar ([EMAIL PROTECTED]) wrote: > > * Evgeniy Polyakov <[EMAIL PROTECTED]> wrote: > > > I posted kevent/epoll benchmarks and related design issues too many > > times both with handmade applications (which might be broken as hell) > > and popular open-source servers to repeat them again. > > numbers are crutial here - and given the epoll bugs in the evserver code > that we found, do you have updated evserver benchmark results that > compare epoll to kevent? I'm wondering why epoll has half the speed of > kevent in those measurements - i suspect some possible benchmarking bug. > The queueing model of epoll and kevent is roughly comparable, both do > only a constant number of steps to serve one particular request, > regardless of how many pending connections/requests there are. What is > the CPU utilization of the server system during an epoll test, and what > is the CPU utilization during a kevent test? 100% utilized in both > cases?
Yes, it is about 98-100% in both cases. I've just re-run tests on my amd64 test machine without debug options: epoll 4794.23 kevent 6468.95 here are full client 'ab' outputs for epoll and kevent servers (epoll does not contain EPOLLET as you requested, but it does not look like it change performance in my case). epoll ab aoutput: # ab -c8000 -n80000 http://192.168.0.48/ This is ApacheBench, Version 2.0.40-dev <$Revision: 1.146 $> apache-2.0 Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/ Copyright 2006 The Apache Software Foundation, http://www.apache.org/ Benchmarking 192.168.0.48 (be patient) Completed 8000 requests Completed 16000 requests Completed 24000 requests Completed 32000 requests Completed 40000 requests Completed 48000 requests Completed 56000 requests Completed 64000 requests Completed 72000 requests Finished 80000 requests Server Software: Apache/1.3.27 Server Hostname: 192.168.0.48 Server Port: 80 Document Path: / Document Length: 3521 bytes Concurrency Level: 8000 Time taken for tests: 16.686737 seconds Complete requests: 80000 Failed requests: 0 Write errors: 0 Total transferred: 309760000 bytes HTML transferred: 281680000 bytes Requests per second: 4794.23 [#/sec] (mean) Time per request: 1668.674 [ms] (mean) Time per request: 0.209 [ms] (mean, across all concurrent requests) Transfer rate: 18128.17 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 159 779 110.1 799 921 Processing: 468 866 77.4 869 988 Waiting: 63 426 212.3 425 921 Total: 1145 1646 115.6 1660 1873 Percentage of the requests served within a certain time (ms) 50% 1660 66% 1661 75% 1662 80% 1663 90% 1806 95% 1830 98% 1833 99% 1834 100% 1873 (longest request) kevent ab output: # ab -c8000 -n80000 http://192.168.0.48/ This is ApacheBench, Version 2.0.40-dev <$Revision: 1.146 $> apache-2.0 Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/ Copyright 2006 The Apache Software Foundation, http://www.apache.org/ Benchmarking 192.168.0.48 (be patient) Completed 8000 requests Completed 16000 requests Completed 24000 requests Completed 32000 requests Completed 40000 requests Completed 48000 requests Completed 56000 requests Completed 64000 requests Completed 72000 requests Finished 80000 requests Server Software: Apache/1.3.27 Server Hostname: 192.168.0.48 Server Port: 80 Document Path: / Document Length: 3521 bytes Concurrency Level: 8000 Time taken for tests: 12.366775 seconds Complete requests: 80000 Failed requests: 0 Write errors: 0 Total transferred: 317047104 bytes HTML transferred: 288306522 bytes Requests per second: 6468.95 [#/sec] (mean) Time per request: 1236.677 [ms] (mean) Time per request: 0.155 [ms] (mean, across all concurrent requests) Transfer rate: 25036.12 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 130 364 871.1 275 9347 Processing: 178 298 42.5 296 580 Waiting: 31 202 65.8 210 369 Total: 411 663 887.0 572 9722 Percentage of the requests served within a certain time (ms) 50% 572 66% 573 75% 618 80% 640 90% 684 95% 709 98% 721 99% 3455 100% 9722 (longest request) Notice how percentage of the requests served within a certain time differs for kevent and epoll. And this server does not include ready-on-submission kevent optimization. > Ingo -- Evgeniy Polyakov - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/