cygwin1.dll and cygstdc++-6.dll account for over 70% of application runtime cost

Mark Geisert
Tue Nov 18 19:27:00 GMT 2014

Corinna Vinschen writes:
> On November 18, 2014 12:54:22 PM CET, Olumide wrote:
> >Thanks Corinna.
> >
> >My application does not explicitly use XSI IPC functions. It's an
> >ordinary C++ application compiled with gcc.
> Your app calls shmat, either the exe or some DLL.
> >BTW, are ZN4muto7releaseEP7_cygtls and ZN4muto7acquireEm also XSI
> >function?
> No, these are Cygwin-internal sync methods, apperantly called quite often

I suspect it's either the IPC functions are called quite often, or the
profiler's timer interrupts are hitting so fast relative to the speed of IPC
that you're always caught on a Windows kernel call (such as an event wait)
underlying Cygwin's IPC implementation.

Looks like the OP would have to debug the app and set a breakpoint at shmat
to determine which DLL is using IPC if the app isn't.


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