Szentirmai Gergely wrote: > Hello > > I had a bad feeling about stack usage (perhaps measurement), and I have > written a small testcode, to see what's really happening. It came with > an interesting result. It seems to me, that cyg_thread_info.stack_used > gives the max used stack size, not the actual. Is that right? According > to the docs, it should give the current usage. > > The test code is attached, I use arm-elf-gcc, ecos with default packages. > > The result is also attached. I think that even the last stack usage > should be equal with 144 Bytes. > > Maybe I am wrong... maybe not.
No, you are correct, the value is the maximum used. Why is this less useful than the 'current' used? Stacks aren't reused or dynamic (they don't grow or shrink), so [IMO] the most useful measurement is the max size you'll ever need, which is the measured value [at the time of the measurement, of course] In addition, every call your code makes to 'diag_printf()' perturbs the measurement, as it can use a lot of stack itself! If you want to be very pure about the measurements, save the stack information in some variables and only print the results when done, that way 'diag_printf()'s use won't get in the way. -- ------------------------------------------------------------ Gary Thomas | Consulting for the MLB Associates | Embedded world ------------------------------------------------------------ -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
