Date: Tue, 11 Nov 2003 02:39:49 -0800 From: Terry Lambert <tlambert2@mindspring.com> To: Alex Wilkinson <alex.wilkinson@dsto.defence.gov.au> Cc: current@freebsd.org Subject: Re: erroneous message from locked-up machine Message-ID: <3FB0BC75.BC0E163E@mindspring.com> References: <20031110164513.GA828@bewilderbeast.blackhelicopters.org> <20031111004523.GE14579@squirm.dsto.defence.gov.au>
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Alex Wilkinson wrote: > Can someone please elaborate on the acronym KVA ? > > $ sysctl -d kern.ipc.maxpipekva > kern.ipc.maxpipekva: Pipe KVA limit > > This doesn't tell me enough. Kernel Virtual Address The fast pipe code in FreeBSD uses page lending between the processes participating in the pipe endpoints, so it uses a set of wired memory to do its job. By definition, this means that it takes a chunk of KVA space in order to get the wired memory. This tunable value is an administrative limit on the amount of KVA that can be used up by pipes. In general, you should never feel this, unless you are doing strange things with your pipes. Massively parallel compiles using pipes to communicate between the compiler stages, for example. -- Terry
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