[Sbcl-devel] Tuning SBCL for large heap usage (>100GB)

[Jianshi H. <jia...@gm...>]

Hi,

I'm using a lot of memory (> 25GB) in my latest project. But it seems
SBCL still isn't happy with the max_map_count setting (I've already
increased it to 262144). I guess I need to increase the
GENCGC-CARD-BYTES.

My question is: what is the best practice for using SBCL with very
large heap? The final benchmark of my program is estimated to use
100GB of memory.

The GC overhead seems hard to eliminate, since in Generational GC,
sb-ext:purify is not implemented. Fortunately, most of the data is
read-only so current I'm saving a core file after reading all the
data.


Error messages are as follows:

An mprotect call failed with ENOMEM. This probably means that the maximum amount
of separate memory mappings was exceeded. To fix the problem, either increase
the maximum with e.g. 'echo 262144 > /proc/sys/vm/max_map_count' or recompile
SBCL with a larger value for GENCGC-CARD-BYTES in
'src/compiler/target/backend-parms.lisp'.


Cheers,
-- 
黄　澗石 (Jianshi Huang)
http://huangjs.net/