On Mon, Mar 26, 2012 at 3:38 PM, 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 > In case of bitmaps O(1) will be if I am checking the value of a particular position. But for finding a free bit it will be O(n/t) , t=sizeof(datatype used beneath)==> O(n), with very very low constants. Since, we're not working with a worker_capacity being very very large these low-valued constants will come into play and prove very helpyful. > > > 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 > > > > > _______________________________________________ > Monkey mailing list > [email protected] > http://lists.monkey-project.com/listinfo/monkey >
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