malloc vs ptmalloc2
das at FreeBSD.ORG
Sun Feb 13 00:21:36 PST 2005
On Sun, Feb 13, 2005, Jason Henson wrote:
> I saw on a few of the lists here how linux uses ptmalloc2 and it
> outperforms bsd's malloc. I tried to do some research into it and
> found PHK's pdf on it and it seems bsd's malloc was ment to be ok in
> most every situation. Because of this it shines when primary storage is
> seriously over committed.
> So here is my question, I use FreeBSD as a desktop and never ever use
> swap(I just don't stress my system enough?), can I use ptmalloc in
> stead of malloc? Like defining SCHED_ULE instead of SCHED_4BSD. Can
> the system malloc be switched out?
With a little bit of work, you should be able to replace
src/lib/libc/stdlib/malloc.c. ptmalloc is much more heavyweight,
but it would probably do better in cases where you have a large
number of threads doing a massive number of malloc/free operations
on a multiprocessor system. Other than that, I don't know enough
details about ptmalloc to speculate, except to say that for most
real-world workloads on modern systems, the impact of the malloc
implementation is likely to be negligible. Of course, test
results would be interesting...
More information about the freebsd-hackers