Hi Richard, On Thu, Jan 28, 2016 at 2:37 PM, Richard Plangger <planri...@gmail.com> wrote: > the file rpython/translator/c/src/stack.h defines MAX_STACK_SIZE. PPC > has a bigger limit than e.g. x86. I experienced that on s390x there is > as well a higher consumption of memory for stack frames (they are > variable sized with a pretty high minimum limit (160 bytes) by the ABI). > > I have two questions: > > 1) The OS (i.e. linux) defines a stack limit (ulimit -s), does pypy > overwrite this value with MAX_STACK_SIZE? > > 2) How would I determine which size is best for s390x? Or how did we > come up with 768kb for x86, and 2.8mb for ppc?
The stack limit is some number that is choosen to correspond to a bit more than 1000 recursive levels of a typical Python program when run by PyPy without JIT, as compiled with a typical "gcc -O3". It's thus very much hand-waving. The limit of 768 KB was done in this way. It's much lower than the stack provided by the OS, so no "ulimit" is needed. I had to pick a higher limit for PPC because 768 KB was definitely too low there. Likely, you should measure more precisely how many levels you get on x86-64 (I think it was around 1400) and pick a value for s390x that gives a similar limit. A bientôt, Armin. _______________________________________________ pypy-dev mailing list pypy-dev@python.org https://mail.python.org/mailman/listinfo/pypy-dev
