Suppress a warning about m_assertbuf being unused.

MFC after: 1 week

Merge ^/head r308227 through r308490.

Fix improper use of "its".

Sponsored by: Dell EMC Isilon

Merge ^/head r305687 through r305890.

Renumber license clauses in sys/kern to avoid skipping #3

Merge ^/head r305431 through r305622.

In m_devget(), if the data fits in a packet header mbuf, check the amount
of data is less than or equal to MHLEN instead of MLEN when placing initial
small packet header at end of mbuf.

Reviewed by:

In m_devget(), if the data fits in a packet header mbuf, check the amount
of data is less than or equal to MHLEN instead of MLEN when placing initial
small packet header at end of mbuf.

Reviewed by: glebius
MFC after: 3 days

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MFH

Sponsored by: The FreeBSD Foundation

kern: for pointers replace 0 with NULL.

These are mostly cosmetical, no functional change.

Found with devel/coccinelle.

MFH

Sponsored by: The FreeBSD Foundation

Plug leak in m_unshare.

m_unshare passes on the source mbuf's flags as-is to m_getcl and this
results in a leak if the flags include M_NOFREE. The fix is to clear
the bits not listed in M_COPYALL b

Plug leak in m_unshare.

m_unshare passes on the source mbuf's flags as-is to m_getcl and this
results in a leak if the flags include M_NOFREE. The fix is to clear
the bits not listed in M_COPYALL before calling m_getcl. M_RDONLY
should probably be filtered out too but that's outside the scope of this
fix.

Add assertions in the zone_mbuf and zone_pack ctors to catch similar
bugs.

Update netmap_get_mbuf to not pass M_NOFREE to m_getcl. It's not clear
what the original code was trying to do but it's likely incorrect.
Updated code is no different functionally but it avoids the newly added
assertions.

Reviewed by: gnn@
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D5698

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Move mbuf provider under SDT to indicate that it is FreeBSD specific
and not a stable interface.

Reviewed by: markj
MFC after: 2 weeks
Sponsored by: Rubicon Communications (Netgate)
Differential Rev

Move mbuf provider under SDT to indicate that it is FreeBSD specific
and not a stable interface.

Reviewed by: markj
MFC after: 2 weeks
Sponsored by: Rubicon Communications (Netgate)
Differential Revision: https://reviews.freebsd.org/D5716

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Add an mbuf provider to DTrace.

The mbuf provider is made up of a set of Statically Defined Tracepoints
which help us look into mbufs as they are allocated and freed. This can be
used to inspect th

Add an mbuf provider to DTrace.

The mbuf provider is made up of a set of Statically Defined Tracepoints
which help us look into mbufs as they are allocated and freed. This can be
used to inspect the buffers or for a simplified mbuf leak detector.

New tracepoints are:

mbuf:::m-init
mbuf:::m-gethdr
mbuf:::m-get
mbuf:::m-getcl
mbuf:::m-clget
mbuf:::m-cljget
mbuf:::m-cljset
mbuf:::m-free
mbuf:::m-freem

There is also a translator for mbufs which gives some visibility into the structure,
see mbuf.d for more details.

Reviewed by: bz, markj
MFC after: 2 weeks
Sponsored by: Rubicon Communications (Netgate)
Differential Revision: https://reviews.freebsd.org/D5682

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Merge ^/head r296007 through r296368.

MFH

Sponsored by: The FreeBSD Foundation

New way to manage reference counting of mbuf external storage.

The m_ext.ext_cnt pointer becomes a union. It can now hold the refcount
value itself. To tell that m_ext.ext_flags flag EXT_FLAG_EMBREF

New way to manage reference counting of mbuf external storage.

The m_ext.ext_cnt pointer becomes a union. It can now hold the refcount
value itself. To tell that m_ext.ext_flags flag EXT_FLAG_EMBREF is used.
The first mbuf to attach a cluster stores the refcount. The further mbufs
to reference the cluster point at refcount in the first mbuf. The first
mbuf is freed only when the last reference is freed.

The benefit over refcounts stored in separate slabs is that now refcounts
of different, unrelated mbufs do not share a cache line.

For EXT_EXTREF mbufs the zone_ext_refcnt is no longer needed, and m_extadd()
becomes void, making widely used M_EXTADD macro safe.

For EXT_SFBUF mbufs the sf_ext_ref() is removed, which was an optimization
exactly against the cache aliasing problem with regular refcounting.

Discussed with: rrs, rwatson, gnn, hiren, sbruno, np
Reviewed by: rrs
Differential Revision: https://reviews.freebsd.org/D5396
Sponsored by: Netflix

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MFH

Sponsored by: The FreeBSD Foundation

Merge ^/head r295544 through r295600.

o Gather all mbuf(9) allocation functions into kern_mbuf.c, and all
mbuf(9) manipulation functions into uipc_mbuf.c. This looks like
the initial intent, but had diffused in the last decade.

o G

o Gather all mbuf(9) allocation functions into kern_mbuf.c, and all
mbuf(9) manipulation functions into uipc_mbuf.c. This looks like
the initial intent, but had diffused in the last decade.

o Gather all declarations in mbuf.h in one place and sort them.

o Uninline m_clget() and m_cljget().

There are no functional changes in this patch.

The patch comes from a larger version, where all mbuf(9) allocation was
uninlined, which allowed to make mbuf(9) UMA zones private to kern_mbuf.c.
The performance impact of the total uninlining is still unclear, so we
are holding on now with larger version.

Together with: melifaro, olivier

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MFH @r294567

MFH

Sponsored by: The FreeBSD Foundation

Merge ^/head r293430 through r293685.

New sendfile(2) syscall. A joint effort of NGINX and Netflix from 2013 and
up to now.

The new sendfile is the code that Netflix uses to send their multiple tens
of gigabits of data per second. The n

New sendfile(2) syscall. A joint effort of NGINX and Netflix from 2013 and
up to now.

The new sendfile is the code that Netflix uses to send their multiple tens
of gigabits of data per second. The new implementation features asynchronous
I/O, when I/O operations are launched, but not awaited to be complete. An
explanation of why such behavior is beneficial compared to old one is
going to be too long for a commit message, so we will skip it here.

Additional features of new syscall are extra flags, which provide an
application more control over data sent. The SF_NOCACHE flag tells
kernel that data shouldn't be cached after it was sent. The SF_READAHEAD()
macro allows to specify readahead size in pages.

The new syscalls is a drop in replacement. No modifications are required
to applications. One can take nginx binary for stable/10 and run it
successfully on head. Although SF_NODISKIO lost its original sense, as now
sendfile doesn't block, and now means something completely different (tm),
using the new sendfile the old way is absolutely safe.

Celebrates: Netflix global launch!
Sponsored by: Nginx, Inc.
Sponsored by: Netflix
Relnotes: yes

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Catch up with head (r291075).

Merge from head

Sponsored by: Gandi.net