Subject: Re: bzero.S and assym.h (Re: CVS commit: syssrc/sys/lib/libkern/arch/powerpc)
To: None <firstname.lastname@example.org>
From: Martin J. Laubach <email@example.com>
Date: 12/02/2001 11:17:38
FYI, I have just backed out that change until we resolve the
problem so people's build won't break.
| | > You should not be depending on a statically defined CACHELINESIZE
| | > since that can vary between different CPU models.
| | I think libc version does not depend on static CACHELINESIZE,
| | but for libkern case, could single port have different CPU models
| | that have different cacheline size?
The libc version does a sysctl to get the cache line size the
first time the bzero routine is called.
The libkern variant (really the same routine with some _KERNEL
ifdefs) tries to extract the CACHELINESIZE definition from
powerpc/cpu.h, since the aforementioned sysctl does (in powerpc/
> return sysctl_rdint(oldp, oldlenp, newp, CACHELINESIZE);
I figured that since the sysctl does nothing else than just
returning that value, it would be OK to use it too. I was not
aware that stuff outside the kernel use libkern too.
So I am soliciting ideas and/or fixes to the problems mentioned
- dependency on assym.h
- use of libkern by non-kernel (but with no working sysctl either,
- how to actually and correctly get at the cache line size
in kernel (do we have to have that dynamic too? if so, I
fear the infrastructure for that is not in yet place, see
the snipped above for the sysctl).
Thanks for your patience so far :)