Linux NFS development
 help / color / mirror / Atom feed
From: "J. Bruce Fields" <bfields@fieldses.org>
To: Patrick Goetz <pgoetz@math.utexas.edu>
Cc: "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
Subject: Re: How are client requests load balanced across multiple nfsd processes?
Date: Wed, 16 Feb 2022 14:50:09 -0500	[thread overview]
Message-ID: <20220216195009.GC29074@fieldses.org> (raw)
In-Reply-To: <715a5da9-a7a1-f2b6-b02b-8cc2712b001d@math.utexas.edu>

On Wed, Feb 16, 2022 at 01:33:55PM -0600, Patrick Goetz wrote:
> On 2/16/22 13:22, J. Bruce Fields wrote:
> >There's no user process that calls "listen"; knfsd's normal rpc handling
> >is all in-kernel.  Incoming rpc's may be handed to any of those 16 tasks
> >for processing.  A single task just runs a loop where it receives an
> >rpc, handles it, and sends a response back.
> >
> 
> How does knfsd decide what user space nfsd process to hand a task
> off to?

To be clear, knfsd tasks never run in userspace at all.

> Is it random, round robin, or something more sophisticated?

It's complicated, and I'd have to look at the code.  It's an
implementation detail that nobody should have to depend on.

> Or does it even matter if nfsd is only handling one request at a
> time anyway?

If you're running with 16 threads, then it can be (oversimplifying a
bit) handling up to 16 requests at a time.

--b.

      reply	other threads:[~2022-02-16 19:50 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-15 22:13 How are client requests load balanced across multiple nfsd processes? Patrick Goetz
2022-02-16 19:22 ` J. Bruce Fields
2022-02-16 19:33   ` Patrick Goetz
2022-02-16 19:50     ` J. Bruce Fields [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220216195009.GC29074@fieldses.org \
    --to=bfields@fieldses.org \
    --cc=linux-nfs@vger.kernel.org \
    --cc=pgoetz@math.utexas.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox