linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: heechul@illinois.edu (heechul Yun)
To: linux-arm-kernel@lists.infradead.org
Subject: A page fault causes exiting from WFI mode for all idling cores?
Date: Sat, 28 May 2011 06:59:10 -0500	[thread overview]
Message-ID: <BANLkTimzoNRS+MynARc3uBz8h6N06FGRQQ@mail.gmail.com> (raw)

While I was investigating page fault handling performance on a quad
core Cortex-A9 ARM processor,?I noticed that whenever there is a
page fault, all idling cores?also?awakened---exiting from WFI instruction
on the idle loop?(and go back to WFI again).

Since the page fault generating program is running on a?single core,
it seems unnecessary to wake up?other idling cores (hence saving
power) as well.

Can anyone tell me if this, exiting from WFI on every page fault, is
correct behavior??If so, why?

Heechul

             reply	other threads:[~2011-05-28 11:59 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-28 11:59 heechul Yun [this message]
2011-06-01 10:14 ` A page fault causes exiting from WFI mode for all idling cores? Catalin Marinas
2011-06-01 12:55   ` Lorenzo Pieralisi
2011-06-01 23:16     ` heechul Yun
2011-06-02  8:33       ` Catalin Marinas

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=BANLkTimzoNRS+MynARc3uBz8h6N06FGRQQ@mail.gmail.com \
    --to=heechul@illinois.edu \
    --cc=linux-arm-kernel@lists.infradead.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).