Date: Tue, 17 Oct 2006 12:11:02 +0930 From: Greg 'groggy' Lehey <grog@FreeBSD.org> To: Olivier Nicole <on@cs.ait.ac.th> Cc: freebsd-questions@freebsd.org Subject: Re: User vs Kernel mode Message-ID: <20061017024102.GO96445@wantadilla.lemis.com> In-Reply-To: <200610170235.k9H2ZElx012419@banyan.cs.ait.ac.th> References: <200610170235.k9H2ZElx012419@banyan.cs.ait.ac.th>
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--vNrHrykRFvLVX6W3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tuesday, 17 October 2006 at 9:35:14 +0700, Olivier Nicole wrote: > Hi, > > I have an application that is running on virtual tty 0, i start it the > following way: > > /etc/ttys > ttyv0 "/usr/libexec/getty Door" cons25 on secure > > /etc/gettytab > Door: :ht:np:sp#115200:al=3Ddoor: > > /etc/passwd > door:*:0:0:Run the door program:/usr/local/door:/usr/local/door/door > > While the application is launched by getty, I would like to know if it > is running in user mode or in kernel mode. Processes always start in kernel mode, because they're started by the kernel. They typically spend most of their time in kernel mode (for example, whenever they're idle or waiting for I/O). An active process may switch back and forward between kernel mode and user mode thousands of times a second. > I think in user mode, and so there is no reason why it should affect > other processes, even if my application had some memory management > problems. A process which spends all its time in user mode is looping :-)=20 Maybe you should describe your problem. Greg -- When replying to this message, please copy the original recipients. If you don't, I may ignore the reply or reply to the original recipients. For more information, see http://www.lemis.com/questions.html See complete headers for address and phone numbers. --vNrHrykRFvLVX6W3 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.3 (FreeBSD) iD8DBQFFNEK+IubykFB6QiMRAmNcAKCrN6f+KCkWmVKjOVBLMKMy1WgdBwCcCOzT DaMboYxNNmkiY6yR8yHVl9w= =n+vE -----END PGP SIGNATURE----- --vNrHrykRFvLVX6W3--
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