All of lore.kernel.org
 help / color / mirror / Atom feed
From: Akira Yokosawa <akiyks@gmail.com>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: perfbook@vger.kernel.org, Akira Yokosawa <akiyks@gmail.com>
Subject: [perfbook] Analogy of Figure 7.11 Locking “Saw Kerf”
Date: Sat, 25 Jun 2022 08:12:09 +0900	[thread overview]
Message-ID: <202dbad7-37db-4d6a-f4d4-6d99180028fc@gmail.com> (raw)

Hi Paul,

I find the analogy of Figure 7.11 hard to grasp.

Whether a lock is global or per-instance, the cost of locking
(saw kerf) is observed only when a CPU/thread does the locking
operation.

In this figure, does each board represent data elements, not a
CPU/thread?  If this is the case, what does the waste of "saw kerf"
mean?

What am I missing?

(I hope I am clear enough on what I don't get...)

        Thanks, Akira

             reply	other threads:[~2022-06-24 23:12 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-24 23:12 Akira Yokosawa [this message]
2022-06-24 23:33 ` [perfbook] Analogy of Figure 7.11 Locking “Saw Kerf” Paul E. McKenney
2022-06-24 23:57   ` Akira Yokosawa
2022-06-25  0:30     ` Paul E. McKenney
2022-06-26  4:34       ` Akira Yokosawa
2022-06-26 14:03         ` Paul E. McKenney

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=202dbad7-37db-4d6a-f4d4-6d99180028fc@gmail.com \
    --to=akiyks@gmail.com \
    --cc=paulmck@kernel.org \
    --cc=perfbook@vger.kernel.org \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.