On Mon, Mar 26, 2012 at 4:08 AM, Davidlohr Bueso <[email protected]> wrote:
> On Mon, 2012-03-26 at 02:56 -0300, Felipe Astroza Araya wrote:
>> Good aproach. It's like a stack (LIFO) of sched_connections BUT I'd prefer a 
>> linked list, because it's simpler. You could use just a "free list" and not 
>> two arrays (stack and queue). When a connection is closed his 
>> sched_connection is returned to the "free list" (head).
>>
>
> It seems to be this is an overkill and the optimization is too small. We
> can always maintain a global variable with the size of current capacity
> - since in a threaded context it would require locking which might lead
> to contention. Another alternative is to keep a bitmap instead of a new
> free_in_queue array. So the bitmap would have a size of work_capacity
> each time a slot is occupied, the corresponding bit is set. Bitmaps are
> O(1) as well and the overhead is just 1 bit per setting

would be possible to create a test case using bitmaps ?

>
>> Another issue in mk_scheduler is mk_sched_get_connection(). This function is 
>> called from mk_conn_write() and mk_sched_remove_client(). The 
>> mk_sched_get_connection()'s complexity is O(work_capacity), is used two 
>> times at least in connection life when it could be avoid completely. 
>> epoll_wait returns a event array and Monkey uses the socket fd as 
>> epoll_event data. That's wrong decision!, epoll_event data should be the 
>> sched_connection and NOT the socket fd. It's possible to improve it, but 
>> need hard work.
>>
>> El 26-03-2012, a las 1:22, Eduardo Silva escribió:
>>
>> > Hi,
>> >
>> > thanks for the patch. Looking with valgrind seems to be optimized a
>> > little bit, screenshot here:
>> >
>> >       http://edsiper.linuxchile.cl/sched_optimization_001.png
>> >
>> > without optimization mk_sched_register() takes 0.40 for 5000 calls,
>> > the same situation but for an optimized code takes 0.36. Its an
>> > improvement.
>> >
>> > Dave, Zeus and Max, what do you think about the patch ?
>> >
>> > cheers,
>> >
>> >
>> > On Sun, Mar 25, 2012 at 9:43 PM, Mahesh Gondi <[email protected]> wrote:
>> >> Hi all,
>> >>
>> >> I made some changes to mk_scheduler.c. First I will explain in brief what 
>> >> I
>> >> did before the results.
>> >>
>> >> In mk_scheduler.c , the mk_sched_register_client serves the purpose of
>> >> adding new client requests to the worker thread queue(everything discussed
>> >> here happens in the thread context). Adding was done by iterating over the
>> >> queue to looking for an available spot to be inserted. When the load on
>> >> server is at near max, then this insertion cost rises to O(work_capacity).
>> >>
>> >> Instead I maintained free spots on the queue(list of client requests
>> >> received), in a simple array of size (work_capacity+1) with each element
>> >> pointing to an index in queue(first element kept a count of number of free
>> >> spots available). Array(arr) contains free spots as pointed by the index
>> >> values stored at the position from 1 to arr[0]. Insertion now only takes a
>> >> constant time. Hence this has contributed in running monkey a bit cheaper.
>> >> Similar modifications are in progress, should help monkey run more and 
>> >> more
>> >> faster . :)
>> >>
>> >> Below are the results
>> >>
>> >> Output I got for running with "siege -c 300 -t 30S 127.0.01:2001",
>> >>
>> >> //WITH CONSTANT TIME INSERTION
>> >> Transactions:                  18051 hits
>> >> Availability:                 100.00 %
>> >> Elapsed time:                  29.96 secs
>> >> Data transferred:              23.48 MB
>> >> Response time:                  0.00 secs
>> >> Transaction rate:             602.50 trans/sec
>> >> Throughput:                   0.78 MB/sec
>> >> Concurrency:                    2.30
>> >> Successful transactions:       18051
>> >> Failed transactions:               0
>> >> Longest transaction:            0.23
>> >> Shortest transaction:           0.00
>> >>
>> >> ============================================
>> >>
>> >> //EARLIER
>> >> Transactions:                  17711 hits
>> >> Availability:                 100.00 %
>> >> Elapsed time:                  30.01 secs
>> >> Data transferred:              23.04 MB
>> >> Response time:                  0.00 secs
>> >> Transaction rate:             590.17 trans/sec
>> >> Throughput:                     0.77 MB/sec
>> >> Concurrency:                    1.18
>> >> Successful transactions:       17711
>> >> Failed transactions:               0
>> >> Longest transaction:            0.17
>> >> Shortest transaction:           0.00
>> >>
>> >> i had taken output for each case just after a fresh restart. Reason for 
>> >> only
>> >> ~600 trans/sec is that it was run ec2 t1.small instance.
>> >>
>> >> Thanks & Regards,
>> >> mahesh gondi
>> >>
>> >> _______________________________________________
>> >> Monkey mailing list
>> >> [email protected]
>> >> http://lists.monkey-project.com/listinfo/monkey
>> >>
>> >
>> >
>> >
>> > --
>> > Eduardo Silva
>> > http://edsiper.linuxchile.cl
>> > http://www.monkey-project.com
>> > _______________________________________________
>> > Monkey mailing list
>> > [email protected]
>> > http://lists.monkey-project.com/listinfo/monkey
>>
>> _______________________________________________
>> Monkey mailing list
>> [email protected]
>> http://lists.monkey-project.com/listinfo/monkey
>>
>
>



-- 
Eduardo Silva
http://edsiper.linuxchile.cl
http://www.monkey-project.com
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