On Nov 19 18:18, Iuliu Rus wrote: > You are right, of course. We initially thought it has to be a > multiple of page_size but it doesn't. I just re-tested with 63k and it > gives good perf too. > We get 600Mbits/second compared with 10Mb for the old default. > Attached the modified patch. > > On Tue, Nov 18, 2014 at 8:43 PM, Corinna Vinschen > <[email protected]> wrote: > > Hi Iuliu, > > > > On Nov 18 19:30, Iuliu Rus wrote: > >> Hello, > >> Google is running Cygwin apps on its 10Gb networks and we are seeing > >> extremely bad performance in a couple of cases. For example, iperf > >> with the defaults results in only 10Mbits/sec. > >> We tracked this down to a combination of non-blocking sockets with > >> Nagle+delayed ack kicking in, since the apps eventually end up sending > >> a very small packets (2 bytes). > >> We have a case open against Microsoft but since everything is moving > >> very slow we would like to work around by picking socket buffers that > >> are multiple of 4k. > > > > Thanks for the patch. One question: > > > >> Change log: > >> 2014-11-18 Iuliu Rus <...> > >> > >> * net.cc Change default values for socket buffers to fix performance > >> on 10Gb networks.
Patch applied. Thanks a lot, Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat
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