Merge ^/head r323559 through r325504.

MFhead@r323635

Include _bitset.h to get BITSET_DEFINE, used to define struct slabbits.

MFC after: 1 week

Widen uk_pgoff, the slab header offset field.

16 bits is only wide enough for kegs with an item size of up to 64KB.
At that size or larger, slab headers are typically offpage because the
item size i

Widen uk_pgoff, the slab header offset field.

16 bits is only wide enough for kegs with an item size of up to 64KB.
At that size or larger, slab headers are typically offpage because the
item size is a multiple of the page size, but there is no requirement
that this be the case.

We can widen the field without affecting the layout of struct uma_keg
since the removal of uk_slabsize in r315077 left an adjacent hole.

PR: 218911
MFC after: 2 weeks

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uma: eliminate uk_slabsize field

The field was not used beyond the initial keg setup stage anyway.

MFC after: 1 month (if ever)

Autotune the number of pages set aside for UMA startup based on the number
of CPUs present. On amd64 this unbreaks the boot for systems with 92 or
more CPUs; the limit will vary on other systems dep

Autotune the number of pages set aside for UMA startup based on the number
of CPUs present. On amd64 this unbreaks the boot for systems with 92 or
more CPUs; the limit will vary on other systems depending on the size of
their uma_zone and uma_cache structures.

The major consumer of pages during UMA startup is the 19 zone structures
which are set up before UMA has bootstrapped itself sufficiently to use
the rest of the available memory: UMA Slabs, UMA Hash, 4 / 6 / 8 / 12 /
16 / 32 / 64 / 128 / 256 Bucket, vmem btag, VM OBJECT, RADIX NODE, MAP,
KMAP ENTRY, MAP ENTRY, VMSPACE, and fakepg. If the zone structures occupy
more than one page, they will not share pages and the number of pages
currently needed for startup is 19 * pages_per_zone + N, where N is the
number of pages used for allocating other structures; on amd64 N = 3 at
present (2 pages are allocated for UMA Kegs, and one page for UMA Hash).

This patch adds a new definition UMA_BOOT_PAGES_ZONES, currently set to 32,
and if a zone structure does not fit into a single page sets boot_pages to
UMA_BOOT_PAGES_ZONES * pages_per_zone instead of UMA_BOOT_PAGES (which
remains at 64). Consequently this patch has no effect on systems where the
zone structure fits into 2 or fewer pages (on amd64, 59 or fewer CPUs), but
increases boot_pages sufficiently on systems where the large number of CPUs
makes this structure larger. It seems safe to assume that systems with 60+
CPUs can afford to set aside an additional 128kB of memory per 32 CPUs.

The vm.boot_pages tunable continues to override this computation, but is
unlikely to be necessary in the future.

Tested on: EC2 x1.32xlarge
Relnotes: FreeBSD can now boot on 92+ CPU systems without requiring
vm.boot_pages to be manually adjusted.
Reviewed by: jeff, alc, adrian
Approved by: re (kib)

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sys/vm: minor spelling fixes in comments.

No functional change.

Merge ^/head r296007 through r296368.

MFH

Sponsored by: The FreeBSD Foundation

Remove UMA_ZONE_REFCNT feature, now unused.

Blessed by: jeff

Merge ^/head r295351 through r295543.

MFH

Sponsored by: The FreeBSD Foundation

Include sys/_task.h into uma_int.h, so that taskqueue.h isn't a
requirement for uma_int.h.

Suggested by: jhb

MFH

Sponsored by: The FreeBSD Foundation

Merge ^/head r294961 through r295350.

Redo r292484. Embed task(9) into zone, so that uz_maxaction is called
in a context that can sleep, allowing consumers of the KPI to run their
drain routines without any extra measures.

Discussed wit

Redo r292484. Embed task(9) into zone, so that uz_maxaction is called
in a context that can sleep, allowing consumers of the KPI to run their
drain routines without any extra measures.

Discussed with: jtl

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MFH r289384-r293170

Sponsored by: The FreeBSD Foundation

MFH @r292599

This includes the pluggable TCP framework and other chnages to the
netstack to track for VNET stability.

Security: The FreeBSD Foundation

Add a safety net to reclaim mbufs when one of the mbuf zones become
exhausted.

It is possible for a bug in the code (or, theoretically, even unusual
network conditions) to exhaust all possible mbufs

Add a safety net to reclaim mbufs when one of the mbuf zones become
exhausted.

It is possible for a bug in the code (or, theoretically, even unusual
network conditions) to exhaust all possible mbufs or mbuf clusters.
When this occurs, things can grind to a halt fairly quickly. However,
we currently do not call mb_reclaim() unless the entire system is
experiencing a low-memory condition.

While it is best to try to prevent exhaustion of one of the mbuf zones,
it would also be useful to have a mechanism to attempt to recover from
these situations by freeing "expendable" mbufs.

This patch makes two changes:

a) The patch adds a generic API to the UMA zone allocator to set a
function that should be called when an allocation fails because the
zone limit has been reached. Because of the way this function can be
called, it really should do minimal work.

b) The patch uses this API to try to free mbufs when an allocation
fails from one of the mbuf zones because the zone limit has been
reached. The function schedules a callout to run mb_reclaim().

Differential Revision: https://reviews.freebsd.org/D3864
Reviewed by: gnn
Comments by: rrs, glebius
MFC after: 2 weeks
Sponsored by: Juniper Networks

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Catch up with HEAD (r280229-r284686).

Merge sync of head

MFH: r281855-r282312

Sponsored by: The FreeBSD Foundation

Revert r281451. It causes a panic/hang early in boot for a number of
users, myself included. The original code is likely papering over a
larger bug that needs to be explored, but for now get things

Revert r281451. It causes a panic/hang early in boot for a number of
users, myself included. The original code is likely papering over a
larger bug that needs to be explored, but for now get things back to
a working state.

Obtained from: Netflix, Inc.
MFC after: immediately

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MFH: r280643-r281852

Sponsored by: The FreeBSD Foundation

Rework r281162. Indeed, the flexible array member is preferable here.

Suggested by: Justin T. Gibbs

MFC after: 3 days