[IronPython] IPyb5 performance

Dino Viehland dinov at microsoft.com
Mon Sep 29 01:55:30 CEST 2008

Also not passing a scope is probably bound to help - especially if the perf critical code is in this file and accesses lots of globals.  Do .Compile, get the DefaultScope, update that w/ the vars you want set, and then just do .Execute().

From: users-bounces at lists.ironpython.com [mailto:users-bounces at lists.ironpython.com] On Behalf Of Jimmy Schementi
Sent: Sunday, September 28, 2008 1:32 PM
To: Discussion of IronPython
Subject: Re: [IronPython] IPyb5 performance

Make that last line call compile and see if it helps. When the Silverlight integration was written that gave a 4x speedup when using top-level functions/variables:


Not sure if that's the case anymore, but it's worth a try.


From: users-bounces at lists.ironpython.com [mailto:users-bounces at lists.ironpython.com] On Behalf Of Ronnie Maor
Sent: Saturday, September 27, 2008 11:22 PM
To: Discussion of IronPython
Subject: [IronPython] IPyb5 performance

Hi all,

I've finally managed to get my code running correctly under IPy2b5 - thanks everyone who helped!

I'm now left with a performance problem. My code seems to run roughly 2 times slower:
* infra tests regressed from 19 seconds in IPy 1.1.1 to 33 seconds in IPy2b5
* application level tests regressed from 375 seconds in 1.1.1 to 705 seconds in IPy2b5
(these are single measurements, but variance is not too big - about 5%)
startup time is also much longer, but I can live with that.

before trying to pinpoint the bottlenecks, I wanted to check I'm not missing something stupid, like turning on optimizations in the DLR...
below is the hosting code I'm using to run the tests. I tried with and without "Debug" flag, and it doesn't seem to change anything (except debug allows me to understand the stack traces). I can also run the infra tests with ipy directly, which showed that -O and -OO don't help either.

Is there something else I should be doing? any tips?

// set up runtime and engine
            Dictionary<string, object> runtimeOptions = new Dictionary<string, object>();
            runtimeOptions["Debug"] = true;
            ScriptRuntime runtime = IronPython.Hosting.Python.CreateRuntime(runtimeOptions);
            runtime.LoadAssembly(typeof(String).Assembly); // Add reference to System
            runtime.LoadAssembly(typeof(Uri).Assembly); // Add reference to mscorlib
            engine = runtime.GetEngine("Python");

// run file as __main__
            engine.SetSearchPaths(new string[] {".", progdir, backend_dir, stdlib_dir});

            List argv = new List();
            for (int i = 2; i < args.Length; ++i)
            engine.GetSysModule().SetVariable("argv", argv);

            mainScope = engine.CreateScope();
            mainScope.SetVariable("__name__", "__main__");
            var main_module = Microsoft.Scripting.Hosting.Providers.HostingHelpers.GetScope(mainScope);
            runtime.Globals.SetVariable("__main__", main_module);

            ScriptSource source = engine.CreateScriptSourceFromFile(filename, Encoding.Default, SourceCodeKind.Statements);
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