[ccache] Problem with using ccache during kernel compilation
ams at codesourcery.com
Tue Jan 21 05:15:21 MST 2014
On 15/01/14 16:16, Piotr Kiszka wrote:
> I am trying to use ccache during kernel building.But there is always
> zero cache hits during second kernel compilation:
I've observed this also. It's annoying!
The problem seems to be something in the way the kernel config
autogenerates the header files. I did find out what it was, but I've
In fact, if you build the kernel, then delete all the .o files, and then
run make again, you *do* get cache hits. "make clean" might be OK too,
I'm not sure. Only if you start from completely clean, or reconfigure,
then it doesn't work. Of course, this is the usual use case.
I don't recall finding a workable solution.
P.s. A nice feature for ccache would be for it to report *why* a cached
result wasn't found. This would only be meaningful in direct-mode, but
still might be helpful. In preprocessor mode, *I* might find a list of
hashes useful, so I could compare between runs, but this wouldn't be
universally helpful, I suspect.
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