From: Ian Kent <raven@themaw.net>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tejun Heo <tj@kernel.org>,
Rick Lindsley <ricklind@linux.vnet.ibm.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Andrew Morton <akpm@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>,
David Howells <dhowells@redhat.com>,
Miklos Szeredi <miklos@szeredi.hu>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 0/6] kernfs: proposed locking and concurrency improvement
Date: Fri, 26 Jun 2020 08:19:50 +0800 [thread overview]
Message-ID: <bdb07787592f6d36ec1317eabd79f36097fd1ec2.camel@themaw.net> (raw)
In-Reply-To: <20200625094317.GA3299764@kroah.com>
On Thu, 2020-06-25 at 11:43 +0200, Greg Kroah-Hartman wrote:
> On Thu, Jun 25, 2020 at 04:15:19PM +0800, Ian Kent wrote:
> > On Tue, 2020-06-23 at 19:13 -0400, Tejun Heo wrote:
> > > Hello, Rick.
> > >
> > > On Mon, Jun 22, 2020 at 02:22:34PM -0700, Rick Lindsley wrote:
> > > > > I don't know. The above highlights the absurdity of the
> > > > > approach
> > > > > itself to
> > > > > me. You seem to be aware of it too in writing: 250,000
> > > > > "devices".
> > > >
> > > > Just because it is absurd doesn't mean it wasn't built that way
> > > > :)
> > > >
> > > > I agree, and I'm trying to influence the next hardware design.
> > > > However,
> > >
> > > I'm not saying that the hardware should not segment things into
> > > however many
> > > pieces that it wants / needs to. That part is fine.
> > >
> > > > what's already out there is memory units that must be accessed
> > > > in
> > > > 256MB
> > > > blocks. If you want to remove/add a GB, that's really 4 blocks
> > > > of
> > > > memory
> > > > you're manipulating, to the hardware. Those blocks have to be
> > > > registered
> > > > and recognized by the kernel for that to work.
> > >
> > > The problem is fitting that into an interface which wholly
> > > doesn't
> > > fit that
> > > particular requirement. It's not that difficult to imagine
> > > different
> > > ways to
> > > represent however many memory slots, right? It'd take work to
> > > make
> > > sure that
> > > integrates well with whatever tooling or use cases but once done
> > > this
> > > particular problem will be resolved permanently and the whole
> > > thing
> > > will
> > > look a lot less silly. Wouldn't that be better?
> >
> > Well, no, I am finding it difficult to imagine different ways to
> > represent this but perhaps that's because I'm blinker eyed on what
> > a solution might look like because of my file system focus.
> >
> > Can "anyone" throw out some ideas with a little more detail than we
> > have had so far so we can maybe start to formulate an actual plan
> > of
> > what needs to be done.
>
> I think both Tejun and I have provided a number of alternatives for
> you
> all to look into, and yet you all keep saying that those are
> impossible
> for some unknown reason.
Yes, those comments are a starting point to be sure.
And continuing on that path isn't helping anyone.
That's why I'm asking for your input on what a solution you
would see as adequate might look like to you (and Tejun).
>
> It's not up to me to tell you what to do to fix your broken
> interfaces
> as only you all know who is using this and how to handle those
> changes.
But it would be useful to go into a little more detail, based on
your own experience, about what you think a suitable solution might
be.
That surely needs to be taken into account and used to guide the
direction of our investigation of what we do.
>
> It is up to me to say "don't do that!" and to refuse patches that
> don't
> solve the root problem here. I'll review these later on (I have
> 1500+
> patches to review at the moment) as these are a nice
> micro-optimization...
Sure, and I get the "I don't want another post and run set of
patches that I have to maintain forever that don't fully solve
the problem" view and any ideas and perhaps a little more detail
on where we might go with this would be very much appreciated.
>
> And as this conversation seems to just going in circles, I think this
> is
> going to be my last response to it...
Which is why I'm asking this, I really would like to see this
discussion change course and become useful.
Ian
next prev parent reply other threads:[~2020-06-26 0:20 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-17 7:37 [PATCH v2 0/6] kernfs: proposed locking and concurrency improvement Ian Kent
2020-06-17 7:37 ` [PATCH v2 1/6] kernfs: switch kernfs to use an rwsem Ian Kent
2020-06-17 7:37 ` [PATCH v2 2/6] kernfs: move revalidate to be near lookup Ian Kent
2020-06-17 7:37 ` [PATCH v2 3/6] kernfs: improve kernfs path resolution Ian Kent
2020-06-17 7:38 ` [PATCH v2 4/6] kernfs: use revision to identify directory node changes Ian Kent
2020-06-17 7:38 ` [PATCH v2 5/6] kernfs: refactor attr locking Ian Kent
2020-06-17 7:38 ` [PATCH v2 6/6] kernfs: make attr_mutex a local kernfs node lock Ian Kent
2020-06-19 15:38 ` [PATCH v2 0/6] kernfs: proposed locking and concurrency improvement Tejun Heo
2020-06-19 20:41 ` Rick Lindsley
2020-06-19 22:23 ` Tejun Heo
2020-06-20 2:44 ` Rick Lindsley
2020-06-22 17:53 ` Tejun Heo
2020-06-22 21:22 ` Rick Lindsley
2020-06-23 23:13 ` Tejun Heo
2020-06-24 9:04 ` Rick Lindsley
2020-06-24 9:27 ` Greg Kroah-Hartman
2020-06-24 13:19 ` Tejun Heo
2020-06-25 8:15 ` Ian Kent
2020-06-25 9:43 ` Greg Kroah-Hartman
2020-06-26 0:19 ` Ian Kent [this message]
2020-06-21 4:55 ` Ian Kent
2020-06-22 17:48 ` Tejun Heo
2020-06-22 18:03 ` Greg Kroah-Hartman
2020-06-22 21:27 ` Rick Lindsley
2020-06-23 5:21 ` Greg Kroah-Hartman
2020-06-23 5:09 ` Ian Kent
2020-06-23 6:02 ` Greg Kroah-Hartman
2020-06-23 8:01 ` Ian Kent
2020-06-23 8:29 ` Ian Kent
2020-06-23 11:49 ` Greg Kroah-Hartman
2020-06-23 9:33 ` Rick Lindsley
2020-06-23 11:45 ` Greg Kroah-Hartman
2020-06-23 22:55 ` Rick Lindsley
2020-06-23 11:51 ` Ian Kent
2020-06-21 3:21 ` Ian Kent
2020-12-10 16:44 ` Fox Chen
2020-12-11 2:01 ` [PATCH " Ian Kent
2020-12-11 2:17 ` Ian Kent
2020-12-13 3:46 ` Ian Kent
2020-12-14 6:14 ` Fox Chen
2020-12-14 13:30 ` Ian Kent
2020-12-15 8:33 ` Fox Chen
2020-12-15 12:59 ` Ian Kent
2020-12-17 4:46 ` Ian Kent
2020-12-17 8:54 ` Fox Chen
2020-12-17 10:09 ` Ian Kent
2020-12-17 11:09 ` Ian Kent
2020-12-17 11:48 ` Ian Kent
2020-12-17 15:14 ` Tejun Heo
2020-12-18 7:36 ` Ian Kent
2020-12-18 8:01 ` Fox Chen
2020-12-18 11:21 ` Ian Kent
2020-12-18 13:20 ` Fox Chen
2020-12-19 0:53 ` Ian Kent
2020-12-19 7:47 ` Fox Chen
2020-12-22 2:17 ` Ian Kent
2020-12-18 14:59 ` Tejun Heo
2020-12-19 7:08 ` Ian Kent
2020-12-19 16:23 ` Tejun Heo
2020-12-19 23:52 ` Ian Kent
2020-12-20 1:37 ` Ian Kent
2020-12-21 9:28 ` Fox Chen
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