whether or not the isr needs to hold Giant when running; Giant-less
operation is also controlled by the setting of debug_mpsafenet
o mark all netisr's except NETISR_IP as needing Giant
o add a GIANT_REQUIRED assertion to the top of netisr's that need Giant
o pickup Giant (when debug_mpsafenet is 1) inside ip_input before
calling up with a packet
o change netisr handling so swi_net runs w/o Giant; instead we grab
Giant before invoking handlers based on whether the handler needs Giant
o change netisr handling so that netisr's that are marked MPSAFE may
have multiple instances active at a time
o add netisr statistics for packets dropped because the isr is inactive
Supported by: FreeBSD Foundation
conservative lock. The problem with the lock-less algorithm is that
it suffers from the ABA problem. Running an application with funnels
a couple of 100kpkts/s through the netgraph system on a dual CPU system
with MPSAFE drivers will panic almost immediatly with the old algorithm.
It may be possible to eliminate the contention between threads that insert
free items into the list and those that get free items by using the
Michael/Scott queue algorithm that has two locks.
of asserting that an mbuf has a packet header. Use it instead of hand-
rolled versions wherever applicable.
Submitted by: Hiten Pandya <hiten@unixdaemons.com>
drain routines are done by swi_net, which allows for better queue control
at some future point. Packets may also be directly dispatched to a netisr
instead of queued, this may be of interest at some installations, but
currently defaults to off.
Reviewed by: hsu, silby, jayanth, sam
Sponsored by: DARPA, NAI Labs
queue items that can be allocated by netgraph and the number of free queue
items that are cached on a private list.
Netgraph places an upper limit on the number of queue items it may allocate.
When there is a large number of netgraph messages travelling through the
system (100k/sec and more) there is a high probability, that messages get
queued at the nodes and netgraph runs out of queue items. In this case the data
flow through netgraph gets blocked. The tuneable for the number of free
items lets one trade memory for performance.
The tunables are also available as read-only sysctls.
PR: kern/47393
Reviewed by: julian
Approved by: jake (mentor)
linker_load_module() instead.
This fixes a bug where the kernel was unable to properly locate and
load a kernel module in vfs_mount() (and probably in the netgraph
code as well since it was using the same function). This is because
the linker_load_file() does not properly search the module path.
Problem found by: peter
Reviewed by: peter
Thanks to: peter
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.
Tested on: i386, alpha, sparc64
Change a prototype.
Add a function version of ng_ref_node() when debugging so
a breakpoint can be set on it.
ng_base.c:
add 'node' as an argument to ng_apply_item so that it is up
to the caller to take over and release the item's reference on
the node. If the release reports back that the node went away
due to the reference going to 0, the caller should cease referencing
the now defunct node. (e.g. the item was a 'kill node' message).
Alter ng_unref_node to report back the residual references as a result.
ng_pptpgre.c:
Don't reference a node after we dropped a reference to it.
(What if it was the last?)
Fixes a node leak reported by Harti Brandt <brandt@fokus.gmd.de>
which was due to an incorrect earlier attempt to fix the
"accessing node after dropping the last reference" problem.
and add a sysctl to pppoe to activate non standard ethertypes
so that idiot ISPs (apparently in France) who use
equipment from idiot suppliers (rumour says 3com)
who use nonstandard ethertypes can still connect.
"yep, sure we do pppoe, we use a different identifier to that dictated in
the standard, but sure it's pppoe!"
sysctl -w net.graph.stupid_isp=1 enables the changeover.
mtx_enter(lock, type) becomes:
mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)
similarily, for releasing a lock, we now have:
mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.
The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.
Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:
MTX_QUIET and MTX_NOSWITCH
The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:
mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.
Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.
Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.
Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.
Finally, caught up to the interface changes in all sys code.
Contributors: jake, jhb, jasone (in no particular order)
also try implement teh documented behaviour in socket nodes
so that when there is only one hook, an unaddressed write/send
will DTRT and send the data to that hook.
(e.g. ethernet nodes are persistent until you rip out the hardware)
Use this support in the ethernet and sample nodes.
Add some more abstraction on the 'item's so that node and
hook reference counting can be checked easier.
Slight man page correction.
Make pppoe type dependent on ethernet type.
Clean up node shutdown a little.
Move a mutex from MTX_SPIN to MTX_DEF (oops)
Fix small ref-counting bug.
remove warning on one2many type.
from a node, but does it via the locking queue, thus ensuring that the
node is locked when it's hook is removed.
Add 'deadnode' and 'deadhook' structures for when a node or hook is
invalidated but not yet freed. (not yet freed)
This version is functional and is aproaching solid..
notice I said APROACHING. There are many node types I cannot test
I have tested: echo hole ppp socket vjc iface tee bpf async tty
The rest compile and "Look" right. More changes to follow.
DEBUGGING is enabled in this code to help if people have problems.
format version number. (userland programs should not need to be
recompiled when the netgraph kernel internal ABI is changed.
Also fix modules that don;t handle the fact that a caller may not supply
a return message pointer. (benign at the moment because the calling code
checks, but that will change)
This clears out my outstanding netgraph changes.
There is a netgraph change of design in the offing and this is to some
extent a superset of soem of the new functionality and some of the old
functionality that may be removed.
This code works as before, but allows some new features that I want to
work with and evaluate. It is the basis for a version of netgraph
with integral locking for SMP use.
This is running on my test machine with no new problems :-)
