* Tom Lane <tgl@sss.pgh.pa.us> [010315 14:54] wrote:
> Alfred Perlstein <bright@wintelcom.net> writes:
> > How many files need to be fsync'd?
>
> Only one.
>
> > If it's more than one, what might work is using mmap() to map the
> > files in adjacent areas, then calling msync() on the entire range,
> > this would allow you to batch fsync the data.
>
> Interesting thought, but mmap to a prespecified address is most
> definitely not portable, whether or not you want to assume that
> plain mmap is ...
Yeah... :(
Evil thought though (for reference):
mmap(anon memory) returns addr1
addr2 = addr1 + maplen
split addr1<->addr2 on points A B and C
mmap(file1 over addr1 to A)
mmap(file2 over A to B)
mmap(file3 over B to C)
mmap(file4 over C to addr2)
It _should_ work, but there's probably some corner cases where it
doesn't.
--
-Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org]