Date: Tue, 20 Jan 2004 09:56:59 +0100 From: des@des.no (Dag-Erling =?iso-8859-1?q?Sm=F8rgrav?=) To: Peter Losher <Peter_Losher@isc.org> Cc: current@freebsd.org Subject: Re: 'kern.maxpipekva exceeded' messages... Message-ID: <xzpr7xvvvz8.fsf@dwp.des.no> In-Reply-To: <200401191506.07789.Peter_Losher@isc.org> (Peter Losher's message of "Mon, 19 Jan 2004 15:06:07 -0800") References: <200401191506.07789.Peter_Losher@isc.org>
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Peter Losher <Peter_Losher@isc.org> writes: > In updating one of our authoritiative name servers to 5.2-REL, we enounte= red=20 > after two days of running, kernel message like: > > kern.maxpipekva exceeded, please see tuning(7). > > appearing to the point to where you couldn't ssh into the box (because ss= hd=20 > died w/ too many files opened). I see so mention of kern.maxpipekva on t= he=20 > tuning man page, and greping only finds kern.ipc entries. > > % sysctl -a | grep pipekva > kern.ipc.maxpipekva: 10485760 > kern.ipc.maxpipekvawired: 5242880 > kern.ipc.pipekva: 131072 > kern.ipc.pipekvawired: 0 > > Are they the same, and if so, what's are the guidelines for increasing th= e=20 > number? yes, the error message is incorrect. here's an excerpt from comment in the kernel sources: * In order to limit the resource use of pipes, two sysctls exist: * * kern.ipc.maxpipekva - This is a hard limit on the amount of pageable * address space available to us in pipe_map. Whenever the amount in use * exceeds half of this value, all new pipes will be created with size * SMALL_PIPE_SIZE, rather than PIPE_SIZE. Big pipe creation will be limit= ed * as well. This value is loader tunable only. * * kern.ipc.maxpipekvawired - This value limits the amount of memory that m= ay * be wired in order to facilitate direct copies using page flipping. * Whenever this value is exceeded, pipes will fall back to using regular * copies. This value is sysctl controllable at all times. * * These values are autotuned in subr_param.c. * * Memory usage may be monitored through the sysctls * kern.ipc.pipes, kern.ipc.pipekva and kern.ipc.pipekvawired. You can set these variables in /boot/loader.conf. DES --=20 Dag-Erling Sm=F8rgrav - des@des.no
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