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From: Jeff Dike <jdike@addtoit.com>
To: Young Koh <young.koh@gmail.com>
Cc: user-mode-linux-devel@lists.sourceforge.net
Subject: Re: [uml-devel] The UML scheduler
Date: Mon, 16 May 2005 12:58:30 -0400	[thread overview]
Message-ID: <20050516165830.GA6731@ccure.user-mode-linux.org> (raw)
In-Reply-To: <3524bf1f05051608377420ae37@mail.gmail.com>

On Mon, May 16, 2005 at 11:37:49AM -0400, Young Koh wrote:
> Thank you for your reply. I have one following question.
> 
> in native Linux, a timer tick goes to the kernel, which has the
> previliege to save the current context and switch the running process.
> But UML kernel is just another user level process, even though it is
> tracing the application processes. in UML case, when a timer tick goes
> to the UML kernel, how does it stop the running process, which is
> another process?

Look at switch_to_{skas,tt}.  In tt mode, it's one process waking another
by writing to a pipe, then sleeping by reading its own pipe.  In skas mode,
it's a longjmp and a memory switch.

				Jeff


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      reply	other threads:[~2005-05-16 17:20 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-05-16 14:30 [uml-devel] The UML scheduler Young Koh
2005-05-16 15:06 ` Jeff Dike
2005-05-16 15:37   ` Young Koh
2005-05-16 16:58     ` Jeff Dike [this message]

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