freebsd-nq/sys/netinet6
John Baldwin 82334850ea Add an external mbuf buffer type that holds multiple unmapped pages.
Unmapped mbufs allow sendfile to carry multiple pages of data in a
single mbuf, without mapping those pages.  It is a requirement for
Netflix's in-kernel TLS, and provides a 5-10% CPU savings on heavy web
serving workloads when used by sendfile, due to effectively
compressing socket buffers by an order of magnitude, and hence
reducing cache misses.

For this new external mbuf buffer type (EXT_PGS), the ext_buf pointer
now points to a struct mbuf_ext_pgs structure instead of a data
buffer.  This structure contains an array of physical addresses (this
reduces cache misses compared to an earlier version that stored an
array of vm_page_t pointers).  It also stores additional fields needed
for in-kernel TLS such as the TLS header and trailer data that are
currently unused.  To more easily detect these mbufs, the M_NOMAP flag
is set in m_flags in addition to M_EXT.

Various functions like m_copydata() have been updated to safely access
packet contents (using uiomove_fromphys()), to make things like BPF
safe.

NIC drivers advertise support for unmapped mbufs on transmit via a new
IFCAP_NOMAP capability.  This capability can be toggled via the new
'nomap' and '-nomap' ifconfig(8) commands.  For NIC drivers that only
transmit packet contents via DMA and use bus_dma, adding the
capability to if_capabilities and if_capenable should be all that is
required.

If a NIC does not support unmapped mbufs, they are converted to a
chain of mapped mbufs (using sf_bufs to provide the mapping) in
ip_output or ip6_output.  If an unmapped mbuf requires software
checksums, it is also converted to a chain of mapped mbufs before
computing the checksum.

Submitted by:	gallatin (earlier version)
Reviewed by:	gallatin, hselasky, rrs
Discussed with:	ae, kp (firewalls)
Relnotes:	yes
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D20616
2019-06-29 00:48:33 +00:00
..
dest6.c
frag6.c Revert r346530 until further. 2019-04-22 19:36:19 +00:00
icmp6.c Fix hostname to be returned in an ICMPv6 NI Reply message defined 2019-05-16 19:09:41 +00:00
icmp6.h
in6_cksum.c
in6_fib.c
in6_fib.h
in6_gif.c Add the check that current VNET is ready and access to srchash is allowed. 2018-10-23 13:11:45 +00:00
in6_ifattach.c Convert all IPv4 and IPv6 multicast memberships into using a STAILQ 2019-06-25 11:54:41 +00:00
in6_ifattach.h
in6_jail.c
in6_mcast.c Convert all IPv4 and IPv6 multicast memberships into using a STAILQ 2019-06-25 11:54:41 +00:00
in6_pcb.c Convert all IPv4 and IPv6 multicast memberships into using a STAILQ 2019-06-25 11:54:41 +00:00
in6_pcb.h
in6_pcbgroup.c
in6_proto.c Update for IETF draft-ietf-6man-ipv6only-flag. 2019-03-06 23:31:42 +00:00
in6_rmx.c Use the new VNET_DEFINE_STATIC macro when we are defining static VNET 2018-07-24 16:35:52 +00:00
in6_rss.c
in6_rss.h
in6_src.c Restore IPV6_NEXTHOP option support that seem was partially broken 2019-05-24 11:45:32 +00:00
in6_var.h Convert all IPv4 and IPv6 multicast memberships into using a STAILQ 2019-06-25 11:54:41 +00:00
in6.c Do not perform DAD on stf(4) interfaces. 2019-03-30 18:00:44 +00:00
in6.h Convert all IPv4 and IPv6 multicast memberships into using a STAILQ 2019-06-25 11:54:41 +00:00
ip6_ecn.h
ip6_fastfwd.c New pfil(9) KPI together with newborn pfil API and control utility. 2019-01-31 23:01:03 +00:00
ip6_forward.c New pfil(9) KPI together with newborn pfil API and control utility. 2019-01-31 23:01:03 +00:00
ip6_gre.c Add GRE-in-UDP encapsulation support as defined in RFC8086. 2019-04-24 09:05:45 +00:00
ip6_id.c ip6_randomflowlabel: Avoid blocking if random(4) is not available 2019-04-23 17:18:20 +00:00
ip6_input.c New pfil(9) KPI together with newborn pfil API and control utility. 2019-01-31 23:01:03 +00:00
ip6_mroute.c Plug some networking sysctl leaks. 2018-11-22 20:49:41 +00:00
ip6_mroute.h
ip6_output.c Add an external mbuf buffer type that holds multiple unmapped pages. 2019-06-29 00:48:33 +00:00
ip6_var.h Convert all IPv4 and IPv6 multicast memberships into using a STAILQ 2019-06-25 11:54:41 +00:00
ip6.h
ip6protosw.h
ip_fw_nat64.h Reapply r345274 with build fixes for 32-bit architectures. 2019-03-19 10:57:03 +00:00
ip_fw_nptv6.h Add ability to use dynamic external prefix in ipfw_nptv6 module. 2018-11-12 11:20:59 +00:00
mld6_var.h Fix refcounting leaks in IPv6 MLD code leading to loss of IPv6 2019-01-24 08:34:13 +00:00
mld6.c In mld_v2_cancel_link_timers() check number of references and disconnect 2019-05-09 07:57:33 +00:00
mld6.h
nd6_nbr.c Extract eventfilter declarations to sys/_eventfilter.h 2019-05-20 00:38:23 +00:00
nd6_rtr.c Fix gateway setup for the interface routes. 2019-05-22 21:20:15 +00:00
nd6.c Extract eventfilter declarations to sys/_eventfilter.h 2019-05-20 00:38:23 +00:00
nd6.h Update for IETF draft-ietf-6man-ipv6only-flag. 2019-03-07 23:03:39 +00:00
pim6_var.h
pim6.h
raw_ip6.c When an IPv6 packet is received for a raw socket which has the 2019-04-19 18:09:37 +00:00
raw_ip6.h
route6.c
scope6_var.h
scope6.c Mechanical cleanup of epoch(9) usage in network stack. 2019-01-09 01:11:19 +00:00
sctp6_usrreq.c Use a macro to set the assoc state. I missed this in r337706. 2018-08-14 08:33:47 +00:00
sctp6_var.h Whitespace changes due to changes in ident. 2018-07-19 20:16:33 +00:00
send.c Use the new VNET_DEFINE_STATIC macro when we are defining static VNET 2018-07-24 16:35:52 +00:00
send.h
tcp6_var.h
udp6_usrreq.c There are three places where we return from a function which entered an 2018-10-09 13:26:06 +00:00
udp6_var.h