Re: Using LMDB safely with fork() and exec()

[Lorenz Bauer <lmb@cloudflare.com>]

On 24 August 2016 at 10:30, Hallvard Breien Furuseth <h.b.furuseth@usit.uio.no> wrote:

On 24. aug. 2016 11:02, Lorenz Bauer wrote:

According to man 2 open O_DIRECT alignment is file system specific from 2.6
onwards, but "usually" 512bytes FWIW. Not sure how that would affect this code.

I gather you mean Linux 2.6.  But O_DIRECT is not Linux-specific, I
don't know of a portable way to ask "is this alignment big enough?",
and the code breaks if we use O_DIRECT when the OS doesn't like it.
So we simply assume the OS page size is OK.

Yes, that makes sense of course. I googled around for documentation on some of the more obscure Unixes, but it is hard to come by.

I don't have legal sign-off yet and am abroad until the beginning of September. I'll pick up submitting the patch then.