Re: NOW: o_direct -- WAS: Re: WARNING in xfs_lwr.c, xfs_write()

[Stewart Smith <stewart@xxxxxxxxxxxxxxxx>]

On Thu, 27 May 2010 10:57:14 -0400, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> On Thu, May 27, 2010 at 11:58:55PM +1000, Stewart Smith wrote:
> > There is O_DIRECT type functionality available on Windows, with similar
> > restrictions for aligned IO too. You have to use the Win32 APIs to do it
> > though, the POSIX ones won't get you it (or more than 2048 files open at
> > once).
> > 
> > In practice we've only ever found Solaris (other than linux) to be
> > reliable with O_DIRECT (at least on UFS... ZFS is... well... I wouldn't
> > run a database server on it yet).
> 
> Solaris doesn't support O_DIRECT either, it instead has a separate
> directio call - just another pointless difference.

Oh yeah, casually forgot about that. Shows how much I'm writing new code
on Solaris that is IO performance critical (on Solaris).

-- 
Stewart Smith