> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf > Of Corinna Vinschen > Sent: Friday, February 08, 2002 12:56 PM > To: cygwin > Subject: Re: unix domain socket with shared memory ? > > > On Thu, Feb 07, 2002 at 11:55:31PM +0100, Ralf Habacker wrote: > > One question: Does unix domain sockets uses localhost address ? >net.cc:cygwin_socketpair() seems to > use first an ip > > adress of zero and later the loopback address. Could this have an effect ? > > Nope. It's probably more secure to use INADDR_LOOPBACK here but > it has nothing to do with speed. > > > I have tried to replace the locations using INADDR_ANY with htonl >(INADDR_LOOPBACK) but recognized no changes. > > I would have lost a bet if that had changed anything.
I should add, it does not have any changes relating to the benchmark results. :-) > > If you look a little deeper you can see, that the read() in unix domain socket >benchmark returns only > 32708 bytes > > > > 1966 1981317 [main] bw_unix 1788 _read: 32708 = read (3, 0xA012048, 65536), errno >0 > > > > while the read() in the tcp benchmark returns 65416 > > > > 2573 7229513 [main] bw_tcp 1792 _read: 65416 = read (3, 0xA012048, 65536), errno 0 > > > > and thats may be a reason for the performance difference. > > Hmm, perhaps. I've just checked in a fix which perhaps changes > that disproportion. Could you please check with the latest from > CVS aggain? > Yes, i will try. > > The main difference between the two benchmarks are the used device /dev/sockstream >against /dev/tcp. > > But don't ask me about the reason why, now I'm left > > That's easily to see in the sources. net.cc? > I have assumed, that there are perhaps some hided implementation difference, which causes this buffer size difference. :- > > returned stable after a few (about 10) returns with the full buffer size of 65536 >in the main > benchmark loop. Could > > this be a bug in the winsock code or is it be caused by timing differences, >because not all data is send early > > enough ? (There are 119 bytes missed) > > Dunno. Winsock overhead, perhaps. > > > BTW2: > > > I'm a bit surprised by your results, though. > > I'm additional surprised that the native unix domain sockets performance under >cygwiwn is only 7% of the linux > > performance with the same hardware, while the tcp performance seems to be >acceptable (64% of the linux > > performance). So my main target is to speed this up. :-) > > That's not a surprise. AF_LOCAL sockets are naturally equaly slow > or slower than AF_INET sockets on Cygwin (why? Exercise for the > reader!) while they are a completely independent implementation > on Linux or other OSes. Your're right, it's not a suprise for someone who know how cygwin implements AF_LOCAL :-), but of the sight from linux, this isn't expected I'm porting kde, which comes from linux or other unix and the contained libs and apps expects a faster implementation of AF_LOCAL. And because I'm trying to speed up kde running, this optimation looks good to me. My question is now, what do you think about this idea with a shared memory implementation of AF_LOCAL ? Ralf -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Bug reporting: http://cygwin.com/bugs.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
