Hi Bruno, I noticed your email and this reminds me of a performance issue with polling that I hit recently with ZMQ. Maybe you can be interested to the following excerpt:
----- just to update on this topic, in case it's useful to others: it turned out that the bottleneck [...] was more on the fact that I was calling zmq_poll() before each zmq_msg_recv() (to implement a timeout on the recv()). The way I fixed the problem was to implement a slightly smarter polling logic: I try to receive with ZMQ_DONTWAIT flag. Then if 0 messages are received, next time a poll() operation with my desidered timeout will be performed before attempting the recv(). If 1 message is received instead then the next time the same recv() (always with ZMQ_DONTWAIT flag) will be repeated. ----- of this email thread: https://lists.zeromq.org/pipermail/zeromq-dev/2017-October/031974.html <https://lists.zeromq.org/pipermail/zeromq-dev/2017-October/031974.html> This changed substantially the performances of my application. But perhaps looking at your testing application, you are adding the zmq_poll() operation on purpose, to test its impact so maybe what I wrote above does not solve anything for you, not sure :) HTH, Francesco 2017-11-13 20:55 GMT+01:00 brunobodin . <[email protected]>: > Hi all > > I ran a couple of test in order to evaluate the cost of polling (on > windows). To do so, I added polling to the local_lat and local_thr tests. > > The code is here > > https://github.com/bbdb68/libzmq/tree/test_polling_cost > > and here is what I noticed : > * since the fix about mempcy of FD_SET structure, the performances of > local_thr are excellent, > close to 1Gb/s ie the hardware thoughtput. > > * when I add the polling, the latency tests seems unaffected, while the > thr test falls to 200Mb/s, > that is a 5x drop > > So here are my questions > > * is this way of testing polling meaningful ? > * how do you explain the difference between latency and thoughput tests > behaviour ? > * what are the result on a linux box ? > > Thanks > > Bruno > > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> > Garanti > sans virus. www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> > <#m_-6006190082856671083_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > > _______________________________________________ > zeromq-dev mailing list > [email protected] > https://lists.zeromq.org/mailman/listinfo/zeromq-dev > >
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