[Pkg-lustre-maintainers] [Lustre-discuss] PAGE_SIZE usage in lustre and a debian fix.

[Andreas Dilger]

On Mar 05, 2007  17:40 -0800, David Brown wrote:
> Okay PAGE_SIZE and friends isn't available for some arches in the
> kernel, in fact the only architectures that PAGE_SIZE and friends are
> available for code that isn't compiled with __KERNEL__ are i386, m32r,
> ppc, s390, sh64, x86_64, so after trying to compile the debian
> packages (which build the userspace components separate from the
> kernel components) on ia64 it failed.
> 
> Attached is a patch to 'fix' the problem the first part of the patch
> is what should be happening. The second part of the patch is a hack to
> get the source to build for debian built ia64 kernels.
> 
> >From comments on the LKML PAGE_SIZE shouldn't ever be used by
> userspace and should be using getpagesize() and perform some functions
> to get the other values (PAGE_MASK and PAGE_SHIFT).

I'm not sure that liblustre has ever been tested on ia64, though of course
it is entirely possible that it works OK.  The value of PAGE_SIZE used by
liblustre is pretty arbitrary I think, a large part of it is just so that
the same code can be used by liblustre and linux.

As for your patch, I haven't looked at it closely, but I'm confused why
you would change PAGE_SIZE -> getpagesize(), and then later make a
#define PAGE_SIZE?  Also, there is no guarantee that the ia64 PAGE_SIZE
is 2^14, though whether liblustre really cares is another matter.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.