Re: Linux 2.4.2 fails to merge mmap areas, 700% slowdown.

[Jamie Lokier]

Jakob Østergaard wrote:
> But the bad case was a garbage collector in GCC.  The mmap tricks seem like
> some you may be inclined to actually use in something like garbage collectors.
> Are we sure that the developers of all other garbage collectors out there
> foresaw this problem and didn't do mmap tricks ?

On this theme, some garbage collectors like to write-protect individual
pages, to detect which pages are modified between generations.  The
kernel has never handled this especially well.  It could be argued that
mprotect() and signal() aren't the right way to get this information
though, and it would be better to add a different mechanism.

-- Jamie