On Friday 02 March 2007 00:38:19 Christoph Hellwig wrote:

quoted

Forgive me if I haven't put enough thought into it, but would it be
useful to create a generic_fallocate() that writes zeroed pages for any
non-existent pages in the range?  I don't know how glibc currently
implements posix_fallocate(), but maybe the kernel could do it more
efficiently, even in generic code.  Maybe we don't care, since the major
file systems can probably do something better in their own code.

I'd be more happy to have the write out zeroes loop in glibc.  And
glibc needs to have it anyway, for older kernels.

A generic_fallocate makes sense to me iff we can do it in the kernel
more significantly more efficiently than in glibc, e.g. by using only
a single page in page cache instead of one for each page to be preallocated.

If  glibc is smart enough to do an optimal implementation, I fully agree
with you.

	Arnd <><