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- From: andrewr@iagu.itd.adelaide.edu.au (Andrew Rutherford)
- Newsgroups: comp.sys.dec
- Subject: Re: can't "kill -9" processes on Ultrix/RISC
- Date: 17 Nov 1992 22:39:33 GMT
- Organization: The University of Adelaide
- Lines: 33
- Message-ID: <1ebsb5INNn37@huon.itd.adelaide.edu.au>
- References: <8291@lhdsy1.lahabra.chevron.com>
- NNTP-Posting-Host: iagu.itd.adelaide.edu.au
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-
- Philip Yzarn de Louraille (yzarn@lhdsy1.lahabra.chevron.com) wrote:
-
- + >On Ultrix/RISC 4.2A we often find processes that
- + >can't be killed (by root, "kill -9") - short of a reboot.
-
- + >Is this expected behaviour under some circumstances?
-
- + Yes, if the process has been swapped out to disk and is not recalled.
- + The problem is why isn't the process recalled?
-
- This occurs because the process has gone into a device wait for
- some reason. It doesn't receive the signals until it comes out of the
- kernel, which (for instance) is why the pagedaemon and swapper can't
- be killed - they always have these little "D"'s beside them if you do a
- "ps aux".
- Philip has pointed out one possible cause - there are a number of
- ways of doing this, usually to do with NFS and servers being down,
- broken automounters, something waiting for the close on a pipe (under some
- systems, not sure about Ultrix).
- There are a huge number of fun things you can do with the mmap()
- call under SunOS, (un?)fortunatly none of these seem to work with OSF/1.
- There are ways of getting rid of processes like this, however it
- involves grubbing around inside the kernel - it is NOT advised and you'll
- probably get the kernel to panic if you miss one small thing. Only do this
- if you were going to bring the machine down anyway.
-
- Andrew.
-
- /*
- * Andrew Rutherford andrewr@itd.adelaide.edu.au
- * +61 8 228 5669 Real Programmers always confuse Christmas and
- * Room 1060, Adelaide Uni Halloween because OCT 31 == DEC 25 !
- */
-