Xref: utzoo comp.unix.sysv286:170 comp.unix.sysv386:8551 comp.unix.xenix.misc:233 comp.unix.xenix.sco:2646 comp.unix.wizards:25798
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!execu!sequoia!rpp386!jfh
From: jfh@rpp386.cactus.org (John F Haugh II)
Newsgroups: comp.unix.sysv286,comp.unix.sysv386,comp.unix.xenix.misc,comp.unix.xenix.sco,comp.unix.wizards
Subject: Pagable Kernels (was: Re: Kernel Definition)
Message-ID: <19342@rpp386.cactus.org>
Date: 30 May 91 11:43:46 GMT
References: <1423@necis.UUCP> <1991May24.065316.27331@thunder.mcrcim.mcgill.edu> <19332@rpp386.cactus.org> <1991May29.201432.1803695@locus.com>
Reply-To: jfh@rpp386.cactus.org (John F Haugh II)
Organization: Lone Star Cat Emporium and BBQ Grill
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In article <1991May29.201432.1803695@locus.com> richard@locus.com (Richard M. Mathews) writes:
>You better hunt out each place where such assumptions are made, and
>either temporarily pin down the pages you need or get a lock for the
>appropiate resource.  And then you better think about deadlock and
>performance implications of keeping things pinned or locked.

Note that the AIX v3 kernel is both pagable and pre-emptable, so you
have the problems even if you pin the pages in memory.  It is quite
fun to discover that the resource you just fondled is at this very
moment being altered by another process thread.  All of the usual
assumptions about "atomic" operations go straight out the window in
this case.
-- 
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