System V bss

brandon at tdi2.UUCP brandon at tdi2.UUCP
Sat Feb 28 03:07:59 AEST 1987


Quoted from <1422 at tekcrl.TEK.COM> ["Re: Sys V kernel bss is a HOG!!!"], by terryl at tekcrl.TEK.COM...
+---------------
| In article <3690002 at nucsrl.UUCP> naim at nucsrl.UUCP (Naim Abdullah) writes:
| >However, I am curious as to why the system V kernel has such a large
| >bss size compared to the bsd kernel (410KB vs. 70KB). The Vax is
|
|      Don't forget, BSD kernels allocate things like the buffer cache, in-
| core inode, open file structures (and oodles and oodles of other goodies)
| DYNAMICALLY at run time. So, at the very least, one should add at least
| 1/2 Meg to the BSD kernel sizes. I don't know anything about System V,
| but I'll bet it does all of its allocation statically, (i.e. at link time).
+---------------

The buffers (NBUF) are *probably* dynamic.  I know they are if NBUF is 0;
it uses 10% of the value of physmem as calculated during boot.  The rest is
all static, and includes some sizeable tables for IPC (msg/shm/sema).

++Brandon
-- 
``for is he not of the Children of Luthien?  Never shall that line fail, though
the years may lengthen beyond count.''  --J. R. R. Tolkien

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