>> The problem seems related to certain long running processes with

quoted text
>> fragmented address spaces.

>>

>> Basically, in order to manage address spaces, the kernel keeps track

>> of a bunch of maps.  Entries in these maps are stored in... map

>> entries.  In certain situations, the kernel can't wait to allocate a

>> map entry, so it grabs one from a static list.  Previously, when they

>> ran out, the kernel paniced.  Now it just says uh oh.  The kernel will

>> merrily go on making more static entries as needed.

>

> the problem is not in the user land.

> the problem is in i386 pmap which abuses kmem_map that is there

> for malloc(9)s use and allocates pv_entries from it.

> this leads to enormous kmem_map fragmentation and unaccounted

> allocations that does not show up in the vmstat and as well leads

> to livelocks (sleeping on kmem_map) and out of space in kmem_map

> panics as well. there is a number of measures to remediate the

> situation proper

> - convert pv_entries allocations to pool (i have a diff if you wanna)

Yes, please. Definitely... and thanks.

FWIW I can bring a spare server online this weekend to keep in the

wings in case something goes completely nutty with the diff, so no

worries about this affecting production per se. :-)
Is the diff against 4.3 or 4.3-current?
> - backend malloc w/ pool (filed in sendbug)

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> - a number of uvm fixes (such as amap ops) that reduce fragmentation.