From: Jeff Dike <jdike@addtoit.com>
To: Krishnappa Abhijith-A21204 <abhijith@motorola.com>
Cc: user-mode-linux-devel@lists.sourceforge.net
Subject: Re: [uml-devel] Regarding context switching in UML.
Date: Mon, 19 Mar 2007 13:40:38 -0400 [thread overview]
Message-ID: <20070319174038.GB11790@c2.user-mode-linux.org> (raw)
In-Reply-To: <0A01463223B8164194908CAC85B66A1201AD3E57@ZMY16EXM67.ds.mot.com>
On Mon, Mar 19, 2007 at 11:01:40AM +0800, Krishnappa Abhijith-A21204 wrote:
> Regarding Context switching in UML.
> Each process running in UML will have corresponding process in HOST.
In tt and skas0 mode, roughly yes.
> So when the context switching in HOST happens, UML has to switch the
> corresponding UML process by saving context etc...
> will this be done by tracing thread.... Also how does process running in
> HOST notifies UML to switch ?
It does so by calling the UML's schedule().
The actual context switching is done by the outgoing process sleeping
after waking up the incoming process.
In tt mode, this is done by using a pipe as a semphore. A sleeping
process is sleeping in read on a pipe, and will be woken up when an
outgoing process writes a byte into the other end.
> Also I've read in one of the article that UML schedules its process by
> itself..? How this is done ?
It has its own scheduler.
The fact that you ask this question, and that you seem to think there
is some sort of special relationship between UML and the host kernel,
suggests that you have some basic misunderstandings.
Jeff
--
Work email - jdike at linux dot intel dot com
-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys-and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
prev parent reply other threads:[~2007-03-19 17:42 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-19 3:01 [uml-devel] Regarding context switching in UML Krishnappa Abhijith-A21204
2007-03-19 17:40 ` Jeff Dike [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=20070319174038.GB11790@c2.user-mode-linux.org \
--to=jdike@addtoit.com \
--cc=abhijith@motorola.com \
--cc=user-mode-linux-devel@lists.sourceforge.net \
/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