Rob/Sysyphus1 wrote in response to: > > From: "Chris Marshall" <[EMAIL PROTECTED]> > > .. > > - Setting WITH_POSIX_THREADS => 1 seems ok for > > the current version of cygwin > > > > - It looks like the Basic/Core/Makefile.PL checks > > for the -lpthread in the link library because of > > a bug on SGI systems. Maybe it would be better > > to rely on whether the perl is multithreaded for > > the automated use threads decision and let the > > SGI work around specifically set to 0 there. > > And yet the Makefile.PL message tells us that "PDL > threads are unrelated to perl threads (usethreads=y)!" > and "Enabling perl threads will not help!". Am I right > in understanding you are telling us that is simply not > so (wrt Cygwin, at least) ?
Sorry, I guess I got loose in my language. The whole discussion was about pthreading the pdl threads by setting the WITH_POSIX_THREADS. > Presumably you still need to link to the pthread > library (-lpthread). How did you achieve that ? Some of the reading I did suggested that the pthreads library must come before the c library or that it could be loaded dynamically. I assumed it was being pulled in somehow---because of my initial success with the 2X performance increase. > I haven't (yet) managed to get this to work on > either Cygwin, Win32 or linux - though that might > just be me. Given the observed performance on the 2Xopteron system, I'm pretty sure there are things I'm missing too. > What's a good way to measure performance > differences between the threaded and unthreaded > PDL builds ? For this I just used the benchmark result from the t/pthread.t test. If you run the test directly then it gives times for the same calculation with and then without pthreads. I saw a factor of two the first case. I haven't had time to track down a pthread specific test case to diagnose further. Nor can I guarantee that all the facts are in or that I have them all straight! Just looking for others' data points for now. Regards, Chris
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