Hi Francesco, thanks for the heads up.
Bruno On Tue, Nov 14, 2017 at 7:26 PM, Francesco <francesco.monto...@gmail.com> wrote: > 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 . <brunobo...@gmail.com>: > >> 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_5550454348728784588_m_-6006190082856671083_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> >> >> _______________________________________________ >> zeromq-dev mailing list >> zeromq-dev@lists.zeromq.org >> https://lists.zeromq.org/mailman/listinfo/zeromq-dev >> >> > > _______________________________________________ > zeromq-dev mailing list > zeromq-dev@lists.zeromq.org > https://lists.zeromq.org/mailman/listinfo/zeromq-dev > >
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