[jira] [Comment Edited] (TS-2137) Use eventfd instread of pthread signal/wait to speed up logging

["Yunkai Zhang (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/TS-2137?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13742876#comment-13742876 ] 

Yunkai Zhang edited comment on TS-2137 at 8/17/13 7:50 AM:
-----------------------------------------------------------

I noticed that the ProtectedQueue in event system is using pthread_cond_singal/wait.

I think, I could abstract a common class so that it can be used for anything need it.

==
I will chnage this issue's title from "Use eventfd instread of pthread signal/wait to speed up logging" to "Use eventfd instread of pthread singal/wait in ATS".

And I'll give V3, just wait...
                
      was (Author: yunkai):
    I noticed that the ProtectedQueue in event system is using pthread_cond_singal/wait.

I think, I could abstract a common class so that it can be used for anything need it.
                  
> Use eventfd instread of pthread signal/wait to speed up logging
> ---------------------------------------------------------------
>
>                 Key: TS-2137
>                 URL: https://issues.apache.org/jira/browse/TS-2137
>             Project: Traffic Server
>          Issue Type: Improvement
>          Components: Logging
>            Reporter: Yunkai Zhang
>            Assignee: Yunkai Zhang
>             Fix For: 3.5.0
>
>         Attachments: 0001-TS-2137-Use-eventfd-instread-of-pthread-signal-wait-.patch, 0001-TS-2137-Use-eventfd-instread-of-pthread-signal-wait-.V2.patch, eventfd_vs_pthread_cond_benchmark.tar.gz
>
>
> At the end of lifetime of each http connection, the logging action will call pthread_cond_signal() to notify flush threads.
> As we known, pthread_cond_signal() need to take lock, it'll cause more context switch than eventfd.
> The logging speed is very important for us which will affect RT, it is worth optimizing. 
> I can confirm that evenfd is supported in Linux platform. 
> Let's optimize it in Linux firstly.
> ===
> I have wrote a simple benchmark program to compare the speed of eventfd and pthread_cond notify mechanism.
> You can get the benchmark program from attachment: https://issues.apache.org/jira/secure/attachment/12598570/eventfd_vs_pthread_cond_benchmark.tar.gz, and test it by yourself if interesting.
> What the program do is that:
> 1) Create 10 producer threads and 1 consumer thread.
> 2) Producer threads will notify consumer concurrently in a loop.
> 3) The consumer thread will receive notification up to a given loop times.
> Here is my testing result, the command line argument is loop times(1000000) of consumer:
> {code}
> [eventfd_vs_pthread_cond_benchmark]$ ls
> main.cc  Makefile
> [eventfd_vs_pthread_cond_benchmark]$ make
> g++ -g -o eventfd_test main.cc -DHAVE_EVENTFD -lpthread
> g++ -g -o pthread_cond_test main.cc -lpthread
> [eventfd_vs_pthread_cond_benchmark]$ ls
> eventfd_test  main.cc  Makefile  pthread_cond_test
> [eventfd_vs_pthread_cond_benchmark]$ time ./eventfd_test 1000000
> real    0m11.644s
> user    0m1.517s
> sys     1m31.179s
> [eventfd_vs_pthread_cond_benchmark]$ time ./pthread_cond_test 1000000
> real    0m57.438s
> user    0m30.152s
> sys     6m7.289s
> {code}
> We can see that eventfd is about 5 times faster than pthread_cond notify mechanism.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira