Re: [PATCH] speedup allocation in pack-redundant.c

Lukas Sandström, Tue, Nov 22, 2005 23:48:51 +0100:

quoted

quoted

Subject: [PATCH] speedup allocation in pack-redundant.c
Reuse discarded nodes of llists
Signed-off-by: Alex Riesen <redacted>

I think making allocation/deallocation to the central place is a
good cleanup, but I am not sure about the free-nodes reusing.
Does this make difference in real life?  If so, it might be
worth doing the slab-like allocation, since free-nodes are very
small structure and malloc overhead is not ignorable there.

I have done some tests, and unfortunatley I saw approx. zero
improvement with Alex's patch. (less than 10ms difference when
total runtime is 1.850s, tested on http://home.arcor.de/fork0/download/idx.tar.gz)

Can I suggest you try it in a really really weird environment? Like
Cygwin. And switch some virus scanner on.

Did someone else notice an improvement?

My test case had over 100k files in it (just don't ask why. Weird
environments, weird projects, ...)

It's a nice idea though. I'll look into doing slab-allocation
for the fun of it, but I'm not really sure that malloc is the
bottleneck.

Yes, it usually is not a bottleneck. I think, it just another
exception.