Stack requirements, why is it so big?

Leon Pollak leonp at
Thu May 4 11:30:29 UTC 2000

Hello, all.
    My application has 16 tasks, which means that, using default
STACK_MINIMUM_SIZE definition (which is 8K for powerpc cpu MPC860), I
must have RTEMS workspace size >> 112K.
    I can't use less because the 'thread create" process checks this and
forces the default minimum size to be used.
    Having the following numbers for code:
librtems_g - 86K
libcsupport - 14k
libc    - 10k
my application 110K
my data - 145K

    this means that I have no memory in my 512K RAM. And all this before
the networking, which I didn't incorporate yet (but for which I have
another bank of 512K RAM).

    Now, in this connection, I have two questions:
1. What are the ideas behind this default definition of the stack to 8K?
The old version of C Application Supplement for 68020 that I have says
that 331 byte is enough. I wasn't able to find the corresponding
document for powerpc. Does it exist?
2. If the figures I mentioned are approximately correct, how do the
people use networking? How much RAM do you have?

I shall be very thankful for the clarification.

leonp at

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