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Re: gcc 3.3 garbage collector defaults
Benjamin Kosnik <bkoz@redhat.com> writes:
> Aaaaaaaaaaghh!!!!!! Why aren't these flags documented!!!!
They are documented, in invoke.texi:
@item ggc-min-expand
GCC uses a garbage collector to manage its own memory allocation. This
parameter specifies the minimum percentage by which the garbage
collector's heap should be allowed to expand between collections.
Tuning this may improve compilation speed; it has no effect on code
generation.
The default is 30%. Setting this parameter and
@option{ggc-min-heapsize} to zero causes a full collection to occur at
every opportunity. This is extremely slow, but can be useful for
debugging.
@item ggc-min-heapsize
Minimum size of the garbage collector's heap before it begins bothering
to collect garbage. The first collection occurs after the heap expands
by @option{ggc-min-expand}% beyond @option{ggc-min-heapsize}. Again,
tuning this may improve compilation speed, and has no effect on code
generation.
The default is 4096 (four megabytes). Setting this parameter very large
effectively disables garbage collection. Setting this parameter and
@option{ggc-min-expand} to zero causes a full collection to occur at
every opportunity.
> Why aren't the defaults sane???
I imagine they were sane for when they were introduced, and have never
been reexamined since?
zw