Re: Not as much ccache win as I expected

[Tim Bird <tim.bird@am.sony.com>]

Oleg Verych wrote:
> And what kinds of source/kconfig changes are made for every build?

I start with a baseline config for an embedded board, then
alter, one at a time, individual config items related to kernel size.
No source changes are made.

I do full removal of the kernel source tree and build area
before the start of each test.

> (any versions, e.g. localversion, .version, aren't important, they are for
> modules ko and vmlinux, afaik)
Ok - this is helpful.

> kbuild is `ccache` on itself. Every *.o.cmd is kind of info `ccache`
> hashes (except things like stderr, gcc version) to check repeated
> rebuilds.
Yeah, I'm pretty impressed with how well kbuild avoids rebuilding
stuff in the first place.

Maybe I should just be grateful for any ccache hits I get.

Thanks,
 -- Tim

=============================
Tim Bird
Architecture Group Chair, CE Linux Forum
Senior Staff Engineer, Sony Corporation of America
=============================