- Remove the only ever written to ift_db_mtx_name member of struct iflib_txq.
- Remove the unused or only ever written to ifr_size, ifr_cq_pidx, ifr_cq_gen
and ifr_lro_enabled members of struct iflib_rxq.
- Consistently spell DMA, RX and TX uppercase in comments, messages etc.
instead of mixing with some lowercase variants.
- Consistently use if_t instead of a mix of if_t and struct ifnet pointers.
- Bring the function comments of _iflib_fl_refill(), iflib_rx_sds_free() and
iflib_fl_setup() in line with reality.
- Judging problem reports, people are wondering what on earth messages like:
"TX(0) desc avail = 1024, pidx = 0"
are trying to indicate. Thus, extend this string to be more like that of
non-iflib(4) Ethernet MAC drivers, notifying about a watchdog timeout due
to which the interface will be reset.
- Take advantage of the M_HAS_VLANTAG macro.
- Use false/true rather than FALSE/TRUE for variables of type bool.
- Use FALLTHROUGH as advocated by style(9).
This change creates an array of port maps indexed by numa domain
for lacp port selection. If we have lacp interfaces in more than
one domain, then we select the egress port by indexing into the
numa port maps and picking a port on the appropriate numa domain.
This is behavior is controlled by the new ifconfig use_numa flag
and net.link.lagg.use_numa sysctl/tunable (both modeled after the
existing use_flowid), which default to enabled.
Reviewed by: bz, hselasky, markj (and scottl, earlier version)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D20060
It's atypical, but not invalid, for a driver to pass no capabilities.
Submitted by: Gerald Aryeetey <aryeeteygerald_rogers.com>
Reviewed by: shurd
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20142
By default, cores are now assigned to queues in a sequential
manner rather than all NICs starting at the first core. On a four-core
system with two NICs each using two queue pairs, the nic:queue -> core
mapping has changed from this:
0:0 -> 0, 0:1 -> 1
1:0 -> 0, 1:1 -> 1
To this:
0:0 -> 0, 0:1 -> 1
1:0 -> 2, 1:1 -> 3
Additionally, a device can now be configured to use separate cores for TX
and RX queues.
Two new tunables have been added, dev.X.Y.iflib.separate_txrx and
dev.X.Y.iflib.core_offset. If core_offset is set, the NIC is not part
of the auto-assigned sequence.
Reviewed by: marius
MFC after: 2 weeks
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D20029
Otherwise tap(4) can be loaded by loader despite being compiled into the
kernel, causing a panic as things try to double-initialize.
PR: 220867
MFC after: 3 days
Previously, a pid check was used to prevent open of the tun(4); this works,
but may not make the most sense as we don't prevent the owner process from
opening the tun device multiple times.
The potential race described near tun_pid should not be an issue: if a
tun(4) is to be handed off, its fd has to have been sent via control message
or some other mechanism that duplicates the fd to the receiving process so
that it may set the pid. Otherwise, the pid gets cleared when the original
process closes it and you have no effective handoff mechanism.
Close up another potential issue with handing a tun(4) off by not clobbering
state if the closer isn't the controller anymore. If we want some state to
be cleared, we should do that a little more surgically.
Additionally, nothing prevents a dying tun(4) from being "reopened" in the
middle of tun_destroy as soon as the mutex is unlocked, quickly leading to a
bad time. Return EBUSY if we're marked for destruction, as well, and the
consumer will need to deal with it. The associated character device will be
destroyed in short order.
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20033
It seems that there should be a better way to handle this, but this seems to
be the more common approach and it should likely get replaced in all of the
places it happens... Basically, thread 1 is in the process of destroying the
tun/tap while thread 2 is executing one of the ioctls that requires the
tun/tap mutex and the mutex is destroyed before the ioctl handler can
acquire it.
This is only one of the races described/found in PR 233955.
PR: 233955
Reviewed by: ae
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20027
As with mlx5en, the idea is to drop unwanted traffic as early
in receive as possible, before mbufs are allocated and anything
is passed up the stack. This can save considerable CPU time
when a machine is under a flooding style DOS attack.
The major change here is to remove the unneeded abstraction where
callers of rxd_frag_to_sd() get back a pointer to the mbuf ring, and
are responsible for NULL'ing that mbuf themselves. Now this happens
directly in rxd_frag_to_sd(), and it returns an mbuf. This allows us
to use the decision (and potentially mbuf) returned by the pfil
hooks. The driver can now recycle mbufs to avoid re-allocation when
packets are dropped.
Reviewed by: marius (shurd and erj also provided feedback)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D19645
This GRE-in-UDP encapsulation allows the UDP source port field to be
used as an entropy field for load-balancing of GRE traffic in transit
networks. Also most of multiqueue network cards are able distribute
incoming UDP datagrams to different NIC queues, while very little are
able do this for GRE packets.
When an administrator enables UDP encapsulation with command
`ifconfig gre0 udpencap`, the driver creates kernel socket, that binds
to tunnel source address and after udp_set_kernel_tunneling() starts
receiving of all UDP packets destined to 4754 port. Each kernel socket
maintains list of tunnels with different destination addresses. Thus
when several tunnels use the same source address, they all handled by
single socket. The IP[V6]_BINDANY socket option is used to be able bind
socket to source address even if it is not yet available in the system.
This may happen on system boot, when gre(4) interface is created before
source address become available. The encapsulation and sending of packets
is done directly from gre(4) into ip[6]_output() without using sockets.
Reviewed by: eugen
MFC after: 1 month
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D19921
tun destruction will not continue until TUN_OPEN is cleared. There are brief
moments in tunclose where the mutex is dropped and we've already cleared
TUN_OPEN, so tun_destroy would be able to proceed while we're in the middle
of cleaning up the tun still. tun_destroy should be blocked until these
parts (address/route purges, mostly) are complete.
PR: 233955
MFC after: 2 weeks
This commit adds new if_alloc_domain() and if_alloc_dev() methods to
allocate ifnets. When called with a domain on a NUMA machine,
ifalloc_domain() will record the NUMA domain in the ifnet, and it will
allocate the ifnet struct from memory which is local to that NUMA
node. Similarly, if_alloc_dev() is a wrapper for if_alloc_domain
which uses a driver supplied device_t to call ifalloc_domain() with
the appropriate domain.
Note that the new if_numa_domain field fits in an alignment pad in
struct ifnet, and so does not alter the size of the structure.
Reviewed by: glebius, kib, markj
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D19930
Give devices that need a MAC a 16-bit allocation out of the FreeBSD
Foundation OUI range. Change the name ether_fakeaddr to ether_gen_addr now
that we're dealing real MAC addresses with a real OUI rather than random
locally-administered addresses.
Reviewed by: bz, rgrimes
Differential Revision: https://reviews.freebsd.org/D19587
stf(4) interfaces are not multicast-capable so they can't perform DAD.
They also did not set IFF_DRV_RUNNING when an address was assigned, so
the logic in nd6_timer() would periodically flag such an address as
tentative, resulting in interface flapping.
Fix the problem by setting IFF_DRV_RUNNING when an address is assigned,
and do some related cleanup:
- In in6if_do_dad(), remove a redundant check for !UP || !RUNNING.
There is only one caller in the tree, and it only looks at whether
the return value is non-zero.
- Have in6if_do_dad() return false if the interface is not
multicast-capable.
- Set ND6_IFF_NO_DAD when an address is assigned to an stf(4) interface
and the interface goes UP as a result. Note that this is not
sufficient to fix the problem because the new address is marked as
tentative and DAD is started before in6_ifattach() is called.
However, setting no_dad is formally correct.
- Change nd6_timer() to not flag addresses as tentative if no_dad is
set.
This is based on a patch from Viktor Dukhovni.
Reported by: Viktor Dukhovni <ietf-dane@dukhovni.org>
Reviewed by: ae
MFC after: 3 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19751
From Jake:
iflib_if_transmit returns ENOBUFS when the device is down, or when the
link isn't active.
This was changed in r308792 from return (0), so that the function
correctly reports an error that it was unable to transmit.
However, using ENOBUFS can cause some network applications to produce
the following or similar errors:
"ping: sendto: No buffer space available"
This is a bit confusing as the real cause of the issue is that the
network device is down.
Replace the ENOBUFS return with ENETDOWN to indicate more clearly that
the reason for the failure to send is due to the network device is
offline.
This will cause the error message to be reported as
"ping: sendto: Network is down"
Submitted by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed by: shurd@, sbruno@, bz@
MFC after: 1 week
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D19652
From Jake:
The iflib_device_register function takes the CTX lock before calling
IFDI_ATTACH_PRE, and releases it upon finishing the registration.
Mirror this process in iflib_pseudo_register, so that we always hold the
CTX lock during the attach process when registering a pseudo interface
or a regular interface.
This was caught by code inspection while attempting to analyze where the
CTX lock was held.
Submitted by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed by: shurd@, erj@
MFC after: 1 week
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D19604
lagg_bcast_start appeared to have a bug in that was using the last
lagg port structure after exiting the epoch that was keeping that
structure alive. However, upon further inspection, the epoch was
already entered by the caller (lagg_transmit), so the epoch enter/exit
in lagg_bcast_start was actually unnecessary.
This commit generally removes uses of the net epoch via LAGG_RLOCK to
protect the list of ports when the list of ports was already protected
by an existing LAGG_RLOCK in a caller, or the LAGG_XLOCK.
It also adds a missing epoch enter/exit in lagg_snd_tag_alloc while
accessing the lagg port structures. An ifp is still accessed via an
unsafe reference after the epoch is exited, but that is true in the
current code and will be fixed in a future change.
Reviewed by: gallatin
MFC after: 1 month
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D19718
Consider a bridge0 with em0 and em1 members. Traffic rx'd by em0 and
transmitted by bridge0 through em1 gets accounted for in IPACKETS/IBYTES
and bridge0 bpf -- assuming it's not unicast traffic destined for em1.
Unicast traffic destined for em1 traffic is not accounted for by any
mechanism, and isn't pushed through bridge0's bpf machinery as any other
packets that pass over the bridge do.
Fix this and simplify GRAB_OUR_PACKETS by bailing out early if it was rx'd
by the interface that it was addressed for. Everything else there is
relevant for any traffic that came in from one member that's being directed
at another member of the bridge.
Reviewed by: kp
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D19614
From Jake:
The iflib core never modifies the isc_driver_version string. Allow
drivers to safely assign pointers to constant buffers by marking this
parameter const.
Submitted by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed by: erj@, gallatin@, jhb@
MFC after: 1 week
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D19577
From Jake:
iflib_fl_setup calculates a suitable buffer size for the Rx mbufs based
on the isc_max_frame_size value that drivers setup. This calculation is
repeated by drivers when programming their hardware with the size of
each Rx buffer.
This can lead to a mismatch where the iflib mbuf size is different from
the expected size of the buffer as programmed by the hardware. This can
lead to unexpected results.
If iflib ever wants to support mbuf sizes larger than one page, every
driver must be updated to account for the new possible buffer sizes.
Fix this by calculating the mbuf size prior to calling IFDI_INIT, and
adding the iflib_get_rx_mbuf_sz function which will expose this value to
drivers, so that they do not repeat the same calculation.
Submitted by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed by: shurd@, erj@
MFC after: 1 week
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D19489
From Jake:
iflib_encap calls bus_dmamap_load_mbuf_sg. Upon it returning EFBIG, an
m_collapse and an m_defrag are attempted to shrink the mbuf cluster to
fit within the DMA segment limitations.
However, if we call m_defrag, and then bus_dmamap_load_mbuf_sg returns
EFBIG on the now defragmented mbuf, we will continuously re-call
bus_dmamap_load_mbuf_sg over and over.
This happens because m_head isn't NULL, and remap is >1, so we don't try
to m_collapse or m_defrag again. The only way we exit the loop is if
m_head is NULL. However, m_head can't be modified by the call to
bus_dmamap_load_mbuf_sg, because we don't pass it as a double pointer.
I believe this will be an incredibly rare occurrence, because it is
unlikely that bus_dmamap_load_mbuf_sg will actually fail on the second
defragment with an EFBIG error. However, it still seems like
a possibility that we should account for.
Fix the exit check to ensure that if remap is >1, we will also exit,
even if m_head is not NULL.
Submitted by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed by: shurd@, gallatin@
MFC after: 1 week
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D19468
and remove possible panic condition.
It is already allowed to sleep in bpfattach[2], since BPF_LOCK was
converted to SX lock in r332388. Also move KASSERT() to the top of
function and make full initialization before bpf_if will be linked
to BPF's list of interfaces.
MFC after: 2 weeks
Some applications forward from/to host rings most or all the
traffic received or sent on a physical interface. In this
cases it is desirable to have more than a pair of RX/TX host
rings, and use multiple threads to speed up forwarding.
This change adds support for multiple host rings. On registering
a netmap port, the user can specify the number of desired receive
and transmit host rings in the nr_host_tx_rings and nr_host_rx_rings
fields of the nmreq_register structure.
MFC after: 2 weeks
At this point, all routes should've already been dropped by removing all
members from the bridge. This condition is in-fact KASSERT'd in the line
immediately above where this nop flush was added.
At this point, all routes should've already been dropped by removing all
members from the bridge. This condition is in-fact KASSERT'd in the line
immediately above where this nop flush was added.
After r345180 we need to have the appropriate vnet context set to delete an
rtnode in bridge_rtnode_destroy().
That's usually the case, but not when it's called by the STP code (through
bstp_notify_rtage()).
We have to set the vnet context in bridge_rtable_expire() just as we do in the
other STP callback bridge_state_change().
Reviewed by: kevans
bridge_rtnode_zone still has outstanding allocations at the time of
destruction in the current model because all of the interface teardown
happens in a VNET_SYSUNINIT, -after- the MOD_UNLOAD has already been
processed. The SYSUNINIT triggers destruction of the interfaces, which then
attempts to free the memory from the zone that's already been destroyed, and
we hit a panic.
Solve this by virtualizing the uma_zone we allocate the rtnodes from to fix
the ordering. bridge_rtable_fini should also take care to flush any
remaining routes that weren't taken care of when dynamic routes were flushed
in bridge_stop.
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D19578
If the spanning tree root interface is removed from the bridge we panic
on the next 'ifconfig'.
While the STP code is notified whenever a bridge member interface is
removed from the bridge it does not clear the bs_root_port. This means
bs_root_port can still point at an bridge_iflist which has been free()d.
The next access to it will panic.
Explicitly check if the interface we're removing in bstp_destroy() is
the root, and if so re-assign the roles, which clears bs_root_port.
Reviewed by: philip
MFC after: 2 weeks
The counters of pf tables are updated outside the rule lock. That means state
updates might overwrite each other. Furthermore allocation and
freeing of counters happens outside the lock as well.
Use counter(9) for the counters, and always allocate the counter table
element, so that the race condition cannot happen any more.
PR: 230619
Submitted by: Kajetan Staszkiewicz <vegeta@tuxpowered.net>
Reviewed by: glebius
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D19558
This has the advantage of being obvious to sniff out the designated prefix
by eye and it has all the right bits set. Comment stolen from ffec.
I've removed bryanv@'s pending question of using the FreeBSD OUI range --
no one has followed up on this with a definitive action, and there's no
particular reason to shoot for it and the administrative overhead that comes
with deciding exactly how to use it.
We currently have two places with identical fake hwaddr generation --
if_vxlan and if_bridge. Lift it into if_ethersubr for reuse in other
interfaces that may also need a fake addr.
Reviewed by: bryanv, kp, philip
Differential Revision: https://reviews.freebsd.org/D19573
PFIL_MEMPTR flag are intentionally providing a memory address that
isn't aligned to pointer alignment. This is done to align an IPv4
or IPv6 header that is expected to follow Ethernet header.
When we return PFIL_REALLOCED we store a pointer to allocated mbuf
at this address. With this change the KPI changes to store the pointer
at aligned address, which usually yields in +2 bytes.
Provide two inlines:
pfil_packet_align() to get aligned pfil_packet_t for a misaligned one
pfil_mem2mbuf() to read out mbuf pointer from misaligned pfil_packet_t
Provide function pfil_realloc(), not used yet, that would convert a
memory pfil_packet_t to an mbuf one.
Reported by: hps
Reviewed by: hps, gallatin
r344504 added an extra ARP_LOG() call in case of an if_output() failure.
It turns out IPv4 can be noisy. In order to not spam the console by default:
(a) add a counter for these events so people can keep better track of how
often it happens, and
(b) add a sysctl to select the default ARP_LOG log level and set it to
INFO avoiding the one (the new) DEBUG level by default.
Claim a spare (1st one after 10 years since the stats were added) in order
to not break netstat from FreeBSD 12->13 updates in the future.
Reviewed by: karels
Differential Revision: https://reviews.freebsd.org/D19490
All changes are hidden behind the EXPERIMENTAL option and are not compiled
in by default.
Add ND6_IFF_IPV6_ONLY_MANUAL to be able to set the interface into no-IPv4-mode
manually without router advertisement options. This will allow developers to
test software for the appropriate behaviour even on dual-stack networks or
IPv6-Only networks without the option being set in RA messages.
Update ifconfig to allow setting and displaying the flag.
Update the checks for the filters to check for either the automatic or the manual
flag to be set. Add REVARP to the list of filtered IPv4-related protocols and add
an input filter similar to the output filter.
Add a check, when receiving the IPv6-Only RA flag to see if the receiving
interface has any IPv4 configured. If it does, ignore the IPv6-Only flag.
Add a per-VNET global sysctl, which is on by default, to not process the automatic
RA IPv6-Only flag. This way an administrator (if this is compiled in) has control
over the behaviour in case the node still relies on IPv4.
From Jake:
"The iflib_fl_setup() function tries to pick various buffer sizes based
on the max_frame_size value defined by the parent driver. However, this
code was wrapped under CONTIGMALLOC_WORKS, which was never actually
defined anywhere.
This same code pattern was used in if_em.c, likely trying to match
what iflib uses.
Since CONTIGMALLOC_WORKS is not defined, remove this dead code from
iflib_fl_setup and if_em.c
Given that various iflib drivers appear to be using a similar
calculation, it might be worth making this buffer size a value that the
driver can peek at in the future."
Submitted by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed by: shurd@
MFC after: 1 week
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D19199
The if_tun cloner is not virtualised, but if_clone_attach() does use a
virtualised list of cloners.
The result is that we can't find the if_tun cloner when we try to remove
a renamed tun interface. Virtualise the cloner, and move the final
cleanup into a sysuninit so that we're sure this happens after all of
the vnet_sysuninits
Note that we need unit numbers to be system-unique (rather than unique
per vnet, as is done by if_clone_simple()). The unit number is used to
create the corresponding /dev/tunX device node, and this node must match
with the interface.
Switch to if_clone_advanced() so that we have control over the unit
numbers.
Reproduction scenario:
jail -c -n foo persist vnet
jexec test ifconfig tun create
jexec test ifconfig tun0 name wg0
jexec test ifconfig wg0 destroy
PR: 235704
Reviewed by: bz, hrs, hselasky
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D19248
Mask off the bits we don't care about when checking that capabilities
of the member interfaces have been disabled as intended.
Submitted by: Ryan Moeller <ryan@ixsystems.com>
Reviewed by: kristof, mav
MFC after: 1 week
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D18924
ratelimiting code. The two modules (lagg and vlan) did have
allocation routines, and even though they are indirect (and
vector down to the underlying interfaces) they both need to
have a free routine (that also vectors down to the actual interface).
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D19032
So far, intr_{g,s}etaffinity(9) take a single int for identifying
a device interrupt. This approach doesn't work on all architectures
supported, as a single int isn't sufficient to globally specify a
device interrupt. In particular, with multiple interrupt controllers
in one system as found on e. g. arm and arm64 machines, an interrupt
number as returned by rman_get_start(9) may be only unique relative
to the bus and, thus, interrupt controller, a certain device hangs
off from.
In turn, this makes taskqgroup_attach{,_cpu}(9) and - internal to
the gtaskqueue implementation - taskqgroup_attach_deferred{,_cpu}()
not work across architectures. Yet in turn, iflib(4) as gtaskqueue
consumer so far doesn't fit architectures where interrupt numbers
aren't globally unique.
However, at least for intr_setaffinity(..., CPU_WHICH_IRQ, ...) as
employed by the gtaskqueue implementation to bind an interrupt to a
particular CPU, using bus_bind_intr(9) instead is equivalent from
a functional point of view, with bus_bind_intr(9) taking the device
and interrupt resource arguments required for uniquely specifying a
device interrupt.
Thus, change the gtaskqueue implementation to employ bus_bind_intr(9)
instead and intr_{g,s}etaffinity(9) to take the device and interrupt
resource arguments required respectively. This change also moves
struct grouptask from <sys/_task.h> to <sys/gtaskqueue.h> and wraps
struct gtask along with the gtask_fn_t typedef into #ifdef _KERNEL
as userland likes to include <sys/_task.h> or indirectly drags it
in - for better or worse also with _KERNEL defined -, which with
device_t and struct resource dependencies otherwise is no longer
as easily possible now.
The userland inclusion problem probably can be improved a bit by
introducing a _WANT_TASK (as well as a _WANT_MOUNT) akin to the
existing _WANT_PRISON etc., which is orthogonal to this change,
though, and likely needs an exp-run.
While at it:
- Change the gt_cpu member in the grouptask structure to be of type
int as used elswhere for specifying CPUs (an int16_t may be too
narrow sooner or later),
- move the gtaskqueue_enqueue_fn typedef from <sys/gtaskqueue.h> to
the gtaskqueue implementation as it's only used and needed there,
- change the GTASK_INIT macro to use "gtask" rather than "task" as
argument given that it actually operates on a struct gtask rather
than a struct task, and
- let subr_gtaskqueue.c consistently use __func__ to print functions
names.
Reported by: mmel
Reviewed by: mmel
Differential Revision: https://reviews.freebsd.org/D19139
o Correct the obvious bugs in the netmap(4) parts:
- No longer check for the existence of DMA maps as bus_dma(9)
is used unconditionally in iflib(4) since r341095.
- Supply the correct DMA tag and map pairs to bus_dma(9)
functions (see also the commit message of r343753).
- In iflib_netmap_timer_adjust(), add synchronization of the
TX descriptors before calling the ift_txd_credits_update
method as the latter evaluates the TX descriptors possibly
updated by the MAC.
- In _task_fn_tx(), wrap the netmap(4)-specific bits in
#ifdef DEV_NETMAP just as done in _task_fn_admin() and
_task_fn_rx() respectively.
o In iflib_fast_intr_rxtx(), synchronize the TX rather than
the RX descriptors before calling the ift_txd_credits_update
method (see also above).
o There's no need to synchronize an RX buffer that is going to
be recycled in iflib_rxd_pkt_get(), yet; it's sufficient to
do that as late as passing RX buffers to the MAC via the
ift_rxd_refill method. Hence, combine that synchronization
with the synchronization of new buffers into a common spot
in _iflib_fl_refill().
o There's no need to synchronize the RX descriptors of a free
list in preparation of the MAC updating their statuses with
every invocation of rxd_frag_to_sd(); it's enough to do this
once before handing control over to the MAC, i. e. before
calling ift_rxd_flush method in _iflib_fl_refill(), which
already performs the necessary synchronization.
o Given that the ift_rxd_available method evaluates the RX
descriptors which possibly have been altered by the MAC,
synchronize as appropriate beforehand. Most notably this
is now done in iflib_rxd_avail(), which in turn means that
we don't need to issue the same synchronization yet again
before calling the ift_rxd_pkt_get method in iflib_rxeof().
o In iflib_txd_db_check(), synchronize the TX descriptors
before handing them over to the MAC for transmission via
the ift_txd_flush method.
o In iflib_encap(), move the TX buffer synchronization after
the invocation of the ift_txd_encap() method. If the MAC
driver fails to encapsulate the packet and we retry with
a defragmented mbuf chain or finally fail, the cycles for
TX buffer synchronization have been wasted. Synchronizing
afterwards matches what non-iflib(4) drivers typically do
and is sufficient as the MAC will not actually start with
the transmission before - in this case - the ift_txd_flush
method is called.
Moreover, for the latter reason the synchronization of the
TX descriptors in iflib_encap() can go as it's enough to
synchronize them before passing control over to the MAC by
issuing the ift_txd_flush() method (see above).
o In iflib_txq_can_drain(), only synchronize TX descriptors
if the ift_txd_credits_update method accessing these is
actually called.
Differential Revision: https://reviews.freebsd.org/D19081
In general, the time savings come from separating the active and
inactive queues lists into separate interface and non-interface queue
lists, and changing the rule and queue tag management from list-based
to hash-bashed.
In HFSC, a linear scan of the class table during each queue destroy
was also eliminated.
There are now two new tunables to control the hash size used for each
tag set (default for each is 128):
net.pf.queue_tag_hashsize
net.pf.rule_tag_hashsize
Reviewed by: kp
MFC after: 1 week
Sponsored by: RG Nets
Differential Revision: https://reviews.freebsd.org/D19131
