Date: Sun, 20 Sep 1998 20:02:26 -0700 From: Mike Smith <mike@smith.net.au> To: zhihuizhang <bf20761@binghamton.edu> Cc: hackers <freebsd-hackers@FreeBSD.ORG> Subject: Re: Question about wiring a page Message-ID: <199809210302.UAA02670@word.smith.net.au> In-Reply-To: Your message of "Sat, 19 Sep 1998 16:06:39 EDT." <Pine.SOL.L3.93.980919155823.25658A-100000@bingsun2>
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> > I read in vm_map_lookup() the following comment: > > /* > * If this page is not pageable, we have to get it for all possible > * accesses. > */ > > Does this mean that even if the map entry is specified as wired, the pages > in its range still have to be faulted in for the very first time? Unless it's prefaulted, even a wired page has to be faulted once to obtain a backing page. > Another question: Can any process wire a page at its own will? There must > be some regulations, otherwise anyone can hog the memory. See the mlock(2) manpage for details on this. There's a per-user resource limit (memorylocked) which governs the per-user limit, however I seem to recall that only root can actually lock memory in core. -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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