Re: Possible O_DIRECT problems ?

Chuck Lever (cel@monkey.org)
Fri, 21 Dec 2001 11:04:45 -0500 (EST)


fyi: the complete patch against 2.4.16 (should work with little or no
modification against 2.4.17) is here:

http://www.citi.umich.edu/projects/nfs-perf/patches/

you'll need to apply inode2file.diff then nfs-odirect11.diff, and it
requires Trond's pathconf patch in order to be completely useful.

because O_DIRECT cannot do small I/O (must be a multiple of a block size),
does fsx work when using it? can someone describe the failures?

On Fri, 21 Dec 2001, GOTO Masanori wrote:

> At Fri, 21 Dec 2001 00:39:42 +0000,
> Dave Jones <davej@codemonkey.org.uk> wrote:
> >
> > On Fri, Dec 21, 2001 at 01:23:45AM +0100, Trond Myklebust wrote:
> >
> > > O_DIRECT for NFS isn't yet merged into the kernel. Are these Chuck
> > > Lever's NFS patches you've been testing?
>
> Where is Chuck's patch ? I searched but didn't find.
>
> > Nope, stock 2.4.17rc2 & 2.5.1.
> > I thought NFS might just ignore the O_DIRECT flag if it didn't
> > understand it yet, I wasn't expecting such a dramatic failure.
>
> Supporting direct_IO with NFS is some meaningful
> for users who have fast NAS server environment, IMHO.
>
> > I just got reminded of the bugs Andrew Morton & some others
> > found in O_DIRECT, so this may be hitting the same problems
> > already found.
>
> No, I think it's another issue, but it may be another bugs...
>
> -- gotom
>

- Chuck Lever

--
corporate:	<cel@netapp.com>
personal:	<chucklever@bigfoot.com>

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/