Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [PATCH 2/2] module: fix bne2 "gave up waiting for init of module libcrc32c" | Date | Wed, 2 Jun 2010 12:45:57 +0930 |
| |
On Tue, 1 Jun 2010 02:49:50 pm Rusty Russell wrote: > I wonder if we should just get rid of !CONFIG_UNLOAD then? I have a soft spot > for it because it keeps us honest and shows how much shit is there simply for > our poor man's pagable kernel. > > Let me compile up a kernel with and without and see what it's really doing > to us...
With a distro-style config (copied Ubuntu then held down Enter on oldconfig) it's: Vmlinux module.o (text/data) Total module size (text/data) With unload 8976331 24144/1036 47255565/3298004 Without unload 8962022 20551/732 47176064/3222068 Without modules 8723931
So, we pay 14k for module unload support, or 0.2%, and 0.3% across the modules themselves. There's real runtime costs, too, but someone would need to annotate and see how often we do inc/dec in a real system.
Not sure that last one is exactly comparable, but it looks like module support is a significant cost...
Cheers, Rusty.
| |