From: "bfields@fieldses.org" <bfields@fieldses.org>
To: Trond Myklebust <trondmy@hammerspace.com>
Cc: "chuck.lever@oracle.com" <chuck.lever@oracle.com>,
"dai.ngo@oracle.com" <dai.ngo@oracle.com>,
"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH RFC v5 0/2] nfsd: Initial implementation of NFSv4 Courteous Server
Date: Tue, 30 Nov 2021 14:01:03 -0500 [thread overview]
Message-ID: <20211130190103.GD8837@fieldses.org> (raw)
In-Reply-To: <978a322ad63bfdd8752b6ff9fbfce129c4c99193.camel@hammerspace.com>
On Tue, Nov 30, 2021 at 04:14:10PM +0000, Trond Myklebust wrote:
> On Tue, 2021-11-30 at 11:05 -0500, Bruce Fields wrote:
> > On Tue, Nov 30, 2021 at 03:36:43PM +0000, Chuck Lever III wrote:
> > > I am a little concerned that we are trying to optimize a case
> > > that won't happen during practice. pynfs does not reflect any
> > > kind of realistic or reasonable client behavior -- it's designed
> > > to test very specific server operations.
> >
> > I wonder how hard this problem would be to hit in normal use. I
> > mean, a
> > few hundred or a thousand clients doesn't sound that crazy. This
> > case
> > depends on an open deny, but you could hit the same problem with file
> > locks. Would it be that weird to have a client trying to get a write
> > lock on a file read-locked by a bunch of other clients?
> >
>
> That's a scenario that is subject to starvation problems anyway.
Yes, if it's hundreds of clients continuously grabbing read locks. But
if it's something like: send all the readers a signal, then request a
write lock as a way to wait for them to finish; then you'd normally
expect to get it soon after the last client drops its lock.
I don't know, maybe that's uncommon.
--b.
next prev parent reply other threads:[~2021-11-30 19:01 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-29 0:56 [PATCH RFC v5 0/2] nfsd: Initial implementation of NFSv4 Courteous Server Dai Ngo
2021-09-29 0:56 ` [PATCH RFC v5 1/2] fs/lock: add new callback, lm_expire_lock, to lock_manager_operations Dai Ngo
2021-09-29 0:56 ` [PATCH RFC v5 2/2] nfsd: Initial implementation of NFSv4 Courteous Server Dai Ngo
2021-10-01 20:53 ` [PATCH RFC v5 0/2] " J. Bruce Fields
2021-10-01 21:41 ` dai.ngo
2021-10-01 23:03 ` J. Bruce Fields
2021-11-16 23:06 ` dai.ngo
2021-11-17 14:14 ` J. Bruce Fields
2021-11-17 17:59 ` dai.ngo
2021-11-17 21:46 ` dai.ngo
2021-11-18 0:34 ` J. Bruce Fields
2021-11-22 3:04 ` dai.ngo
2021-11-29 17:13 ` dai.ngo
2021-11-29 17:30 ` J. Bruce Fields
2021-11-29 18:32 ` dai.ngo
2021-11-29 19:03 ` Chuck Lever III
2021-11-29 19:13 ` Bruce Fields
2021-11-29 19:39 ` dai.ngo
2021-11-29 19:36 ` dai.ngo
2021-11-29 21:01 ` dai.ngo
2021-11-29 21:10 ` Chuck Lever III
2021-11-30 0:11 ` dai.ngo
2021-11-30 1:42 ` Chuck Lever III
2021-11-30 4:08 ` Trond Myklebust
2021-11-30 4:47 ` Chuck Lever III
2021-11-30 4:57 ` Trond Myklebust
2021-11-30 7:22 ` dai.ngo
2021-11-30 13:37 ` Trond Myklebust
2021-12-01 3:52 ` dai.ngo
2021-12-01 14:19 ` bfields
2021-11-30 15:36 ` Chuck Lever III
2021-11-30 16:05 ` Bruce Fields
2021-11-30 16:14 ` Trond Myklebust
2021-11-30 19:01 ` bfields [this message]
2021-11-30 7:13 ` dai.ngo
2021-11-30 15:32 ` Bruce Fields
2021-12-01 3:50 ` dai.ngo
2021-12-01 14:36 ` Bruce Fields
2021-12-01 14:51 ` Bruce Fields
2021-12-01 18:47 ` dai.ngo
2021-12-01 19:25 ` Bruce Fields
2021-12-02 17:53 ` Chuck Lever III
2021-12-01 17:42 ` Bruce Fields
2021-12-01 18:03 ` Bruce Fields
2021-12-01 19:50 ` Bruce Fields
2021-12-03 21:22 ` Bruce Fields
2021-12-03 21:55 ` [PATCH] nfsdcld: use WAL journal for faster commits Bruce Fields
2021-12-03 22:07 ` Chuck Lever III
2021-12-03 22:39 ` Bruce Fields
2021-12-04 0:35 ` Chuck Lever III
2021-12-04 1:24 ` Bruce Fields
2021-12-06 15:46 ` Chuck Lever III
2022-01-04 22:24 ` Bruce Fields
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