Although, over thanksgiving, I pushed a number of fixes which should improve the quality of backtraces on win32 (and make sys.dll usable there) On Tue, Dec 2, 2014 at 1:20 PM Jameson Nash <[email protected]> wrote:
> 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 <[email protected]> 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 >> >>
