From: Trond Myklebust <Trond.Myklebust@netapp.com>
To: Chuck Lever <chuck.lever@oracle.com>
Cc: linux-nfs@vger.kernel.org
Subject: Re: [PATCH 2/2] NFS: Don't generate a GETATTR when opening an O_DIRECT file
Date: Thu, 11 Feb 2010 14:34:01 -0500 [thread overview]
Message-ID: <1265916841.478.31.camel@localhost> (raw)
In-Reply-To: <4B745872.7020807@oracle.com>
On Thu, 2010-02-11 at 14:20 -0500, Chuck Lever wrote:
> On 02/11/2010 02:14 PM, Trond Myklebust wrote:
> > On Thu, 2010-02-11 at 14:09 -0500, Chuck Lever wrote:
> >> Close-to-open isn't needed for O_DIRECT files, since their data is
> >> never cached. So if their attribute cache hasn't expired, skip the
> >> GETATTR.
> >
> > Don't we still want to ensure that the access cache is still valid?
>
> Would it be reasonable/feasible to squelch the GETATTR but force an
> ACCESS call from nfs_permission?
As long as the ACCESS call returns post-op attributes, then it is
reasonable to do this for NFSv3 (or for NFSv4 opendir()) in all cases.
I used to have patches for this, but was never able to show that the
resulting total number of GETATTR+ACCESS calls was much affected.
Cheers
Trond
next prev parent reply other threads:[~2010-02-11 19:34 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-11 19:08 [PATCH 0/2] Reduce GETATTRs during direct I/O Chuck Lever
[not found] ` <20100211185757.2666.90001.stgit-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2010-02-11 19:09 ` [PATCH 1/2] NFS: Too many GETATTR and ACCESS calls after " Chuck Lever
2010-02-11 19:09 ` [PATCH 2/2] NFS: Don't generate a GETATTR when opening an O_DIRECT file Chuck Lever
[not found] ` <20100211190918.2666.82008.stgit-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2010-02-11 19:13 ` Chuck Lever
2010-02-11 19:14 ` Trond Myklebust
2010-02-11 19:20 ` Chuck Lever
2010-02-11 19:34 ` Trond Myklebust [this message]
2010-02-11 19:41 ` Chuck Lever
2010-02-11 19:45 ` Trond Myklebust
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