Correct. Windows imposes a much higher overhead on just about every aspect of doing profiling. Unfortunately, there isn't much we can do about this, other then to complain to Microsoft. (It doesn't have signals, so we must emulate them with a separate thread. The accuracy of windows timers is somewhat questionable. And the stack walk library (for recording the backtrace) is apparently just badly written and therefore insanely slow and memory hungry.) On Tue, Dec 2, 2014 at 12:59 PM Tim Holy <tim.h...@gmail.com> wrote:
> I think it's just that Windows is bad at scheduling tasks with > short-latency, > high-precision timing, but I am not the right person to answer such > questions. > > --Tim > > On Tuesday, December 02, 2014 09:57:28 AM Peter Simon wrote: > > I have also experienced the inaccurate profile timings on Windows. Is > the > > reason for the bad profiler performance on Windows understood? Are there > > plans for improvement? > > > > Thanks, > > --Peter > > > > On Tuesday, December 2, 2014 3:57:16 AM UTC-8, Tim Holy wrote: > > > By default, the profiler takes one sample per millisecond. In practice, > > > the > > > timing is quite precise on Linux, seemingly within a factor of twoish > on > > > OSX, > > > and nowhere close on Windows. So at least on Linux you can simply read > > > samples > > > as milliseconds. > > > > > > If you want to visualize the relative contributions of each statement, > I > > > highly recommend ProfileView. If you use LightTable, it's already > built-in > > > via > > > the profile() command. The combination of ProfileView and @profile is, > in > > > my > > > (extremely biased) opinion, quite powerful compared to tools I used > > > previously > > > in other programming environments. > > > > > > Finally, there's IProfile.jl, which works via a completely different > > > mechanism > > > but does report raw timings (with some pretty big caveats). > > > > > > Best, > > > --Tim > > > > > > On Monday, December 01, 2014 10:13:16 PM Christoph Ortner wrote: > > > > How do you get timings from the Julia profiler, or even better, > %-es? I > > > > guess one can convert from the numbers one gets, but it is a bit > > > > > > painful? > > > > > > > Christoph > >
