https://bugzilla.novell.com/show_bug.cgi?id=652522
https://bugzilla.novell.com/show_bug.cgi?id=652522#c0 Summary: Parallel.For is 100 times slower than sequential for, at the same time Parallel.For with Partitioner is ok Classification: Mono Product: Mono: Class Libraries Version: SVN Platform: All OS/Version: All Status: NEW Severity: Normal Priority: P5 - None Component: Sys.Core AssignedTo: [email protected] ReportedBy: [email protected] QAContact: [email protected] Found By: --- Blocker: --- User-Agent: Opera/9.80 (Windows NT 6.1; U; pl) Presto/2.6.30 Version/10.63 Parallel.For (without partitioner) is 200 times slower than sequential for on 4-logical core machines (I've tried on two computers) I have runned microsoft's example "ComputePi" (http://blogs.msdn.com/b/pfxteam/archive/2009/12/09/9934811.aspx or http://code.msdn.microsoft.com/ParExtSamples) on mono 2.9 (from trunk) ( Mono 2.8 throws NotImplemented Exception) Here are the execution times: SerialLinq: 00:00:16.5024978 ParallelLinq: 00:00:26.0804742 Serial: 00:00:00.9266276 Parallel: 00:03:04.7353892 ParallelPartitioner 00:00:00.5463789 Above values are really strange, parallel version time (3 minutes !) is slower than serial one, at the same time the new parallel partitioner result is ok I've also tried running in .net program compiled on mono and results are ok (other computer results): SerialLinq: 00:00:08.5200829 ParallelLinq: 00:00:02.6109864 Serial: 00:00:02.2807189 Parallel: 00:00:01.2737228 ParallelPartitioner 00:00:00.7517575 Reproducible: Always Steps to Reproduce: 1. run 'ComputePi' Microsoft's parallel example (http://code.msdn.microsoft.com/ParExtSamples) Actual Results: (approximately) 00:00:16.5024978 00:00:26.0804742 00:00:00.9266276 00:03:04.7353892 00:00:00.5463789 Expected Results: (approximately) 00:00:08.5200829 00:00:02.6109864 00:00:02.2807189 00:00:01.2737228 00:00:00.7517575 -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the QA contact for the bug. _______________________________________________ mono-bugs maillist - [email protected] http://lists.ximian.com/mailman/listinfo/mono-bugs
