On Thu, 10 Sep 2015, Ludovic Courtès wrote:
>  GC_INITIAL_HEAP_SIZE=<bytes> -	Initial heap size in bytes.  May speed up
>                                  process start-up.
>
>  GC_MAXIMUM_HEAP_SIZE=<bytes> - Maximum collected heap size.
>
>  GC_MARKERS=<n> - Linux w/threads and parallel marker only.  Set the number
>                  of marker threads.  This is normally set to the number of
>                  processors.  It is safer to adjust GC_MARKERS than GC_NPROCS,
>                  since GC_MARKERS has no impact on the lock implementation.
>
> Guile also honors the ‘GC_FREE_SPACE_DIVISOR’ environment variable.  See
> the comments in gc.h for the meaning of this one.
>
> HTH,
> Ludo’.
Hi Ludovic,
Increasing the initial heap size already improves the performance a lot:

     $ make bench
     ...
     make[1]: Entering directory '/home/jan/test/aiscm/bench'
     LD_LIBRARY_PATH=../aiscm/.libs:../bench/.libs:/usr/local/lib GC_INITIAL_HEAP_SIZE=1G GC_USE_ENTIRE_HEAP=Y /usr/bin/guile --no-auto-compile -L .. bench.scm
                                            user     system      total        real
     Guile GOOPS method dispatch        0.000110   0.000000   0.000110 (  0.000100)
     Guile make empty sequence          0.000640   0.000000   0.000640 (  0.000640)
     Guile allocate memory              0.000210   0.000000   0.000210 (  0.000210)
     Guile negate empty sequence        0.002950   0.000080   0.003030 (  0.003020)
     Guile make sequence                0.000740   0.000000   0.000740 (  0.000740)
     Guile negate sequence              0.003960   0.000490   0.004450 (  0.004460)
     C allocate memory                  0.000080   0.000000   0.000080 (  0.000070)
     C negate empty sequence            0.000050   0.000000   0.000050 (  0.000060)
     C negate sequence                  0.000740   0.000000   0.000740 (  0.000740)
     make[1]: Leaving directory '/home/jan/test/aiscm/bench'

I'll try to understand the free space divisor later.
Many thanks

Jan