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Re: more on the "vmmapva" kernel deadlocks on NetBSD-4

At Fri, 19 Jun 2009 12:35:40 -0400, "Greg A. Woods" 
<> wrote:
Subject: Re: more on the "vmmapva" kernel deadlocks on NetBSD-4
> Well my server ran a bit longer and handled some fair workload
> yesterday, but it still wedged overnight.  The most likely first-hung
> process was a "find" started by one of the nightly cron jobs.
> That was with "options BUFCACHE" left at the default of 15%, but with
> vm.bufmem manually set back down to 10%.
> I may be wrong about this, but IIUC the manual setting won't free up and
> re-allocate all of the buffer memory tables, etc., just restrict their
> use -- BUFCACHE has to be set lower at boot to actually avoid allocating
> more space than needed.  I'm about to reboot another kernel with
> BUFCACHE set to 5% and we'll see how it does.

Well, if it means anything my server lived through the night without any
problems after rebooting with the BUFCACHE=5 kernel.

Now to do some debugging and find out what the numbers actually are to
see if I can code some reasonable heuristic for limiting BUFCACHE at
boot automatically.

                                                Greg A. Woods
                                                Planix, Inc.

<>       +1 416 218-0099

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