In particular, do not lock Giant conditionally when calling into the
filesystem module, remove the VFS_LOCK_GIANT() and related
macros. Stop handling buffers belonging to non-mpsafe filesystems.
The VFS_VERSION is bumped to indicate the interface change which does
not result in the interface signatures changes.
Conducted and reviewed by: attilio
Tested by: pho
Function acquired reader lock if needed.
Assert check for reader or writer lock (RA_LOCKED / RA_UNLOCKED)
- While here, add knlist_init_mtx.9 to MLINKS and fix some style(9) issues
Reviewed by: glebius
Approved by: ae(mentor)
MFC after: 2 weeks
- Document the following routines: pci_alloc_msi(), pci_alloc_msix(),
pci_find_cap(), pci_get_max_read_req(), pci_get_vpd_ident(),
pci_get_vpd_readonly(), pci_msi_count(), pci_msix_count(),
pci_pending_msix(), pci_release_msi(), pci_remap_msix(), and
pci_set_max_read_req().
- Group the functions into five sub-sections: raw configuration access,
locating devices, device information, device configuration, and
message signaled interrupts.
- Discourage use of pci_disable_io() and pci_enable_io() in device drivers.
The PCI bus driver handles this automatically as resources are activated.
MFC after: 2 weeks
pci_cfg_save() and pci_cfg_restore() for device drivers to use when
saving and restoring state (e.g. to handle device-specific resets).
Reviewed by: imp
MFC after: 2 weeks
I was considering adding it to libc as well, but last minute I thought
it would be good enough to add it to libkern exclusively. I forgot to
rename the man page and hook it up.
objects created by shm_open(2) into the kernel's address space. This
provides a convenient way for creating shared memory buffers between
userland and the kernel without requiring custom character devices.
curthread-accessing part of mtx_{,un}lock(9) when using a r210623-style
curthread implementation on sparc64, crashing the kernel in its early
cycles as PCPU isn't set up, yet (and can't be set up as OFW is one of the
things we need for that, which leads to a chicken-and-egg problem). What
happens is that due to the fact that the idea of r210623 actually is to
allow the compiler to cache invocations of curthread, it factors out
obtaining curthread needed for both mtx_lock(9) and mtx_unlock(9) to
before the branch based on kobj_mutex_inited when compiling the kernel
without the debugging options. So change kobj_class_compile_static(9)
to just never acquire kobj_mtx, effectively restricting it to its
documented use, and add a kobj_init_static(9) for initializing objects
using a class compiled with the former and that also avoids using mutex(9)
(and malloc(9)). Also assert in both of these functions that they are
used in their intended way only.
While at it, inline kobj_register_method() and kobj_unregister_method()
as there wasn't much point for factoring them out in the first place
and so that a reader of the code has to figure out the locking for
fewer functions missing a KOBJ_ASSERT.
Tested on powerpc{,64} by andreast.
Reviewed by: nwhitehorn (earlier version), jhb
MFC after: 3 days
mod_cc.4 and mod_cc.9 respectively to avoid any possible confusion with the cc.1
gcc man page. Update references to these man pages where required.
Requested by: Grenville Armitage
Approved by: re (kib)
MFC after: 3 days
If a selinfo object is recorded (via selrecord()) and then it is
quickly destroyed, with the waiters missing the opportunity to awake,
at the next iteration they will find the selinfo object destroyed,
causing a PF#.
That happens because the selinfo interface has no way to drain the
waiters before to destroy the registered selinfo object. Also this
race is quite rare to get in practice, because it would require a
selrecord(), a poll request by another thread and a quick destruction
of the selrecord()'ed selinfo object.
Fix this by adding the seldrain() routine which should be called
before to destroy the selinfo objects (in order to avoid such case),
and fix the present cases where it might have already been called.
Sometimes, the context is safe enough to prevent this type of race,
like it happens in device drivers which installs selinfo objects on
poll callbacks. There, the destruction of the selinfo object happens
at driver detach time, when all the filedescriptors should be already
closed, thus there cannot be a race.
For this case, mfi(4) device driver can be set as an example, as it
implements a full correct logic for preventing this from happening.
Sponsored by: Sandvine Incorporated
Reported by: rstone
Tested by: pluknet
Reviewed by: jhb, kib
Approved by: re (bz)
MFC after: 3 weeks
wrapper around rman_adjust_resource(). Include a generic implementation,
bus_generic_adjust_resource() which passes the request up to the parent
bus. There is currently no default implementation. A
bus_adjust_resource() wrapper is provided for use in drivers.
Specifically, these changes allow a resource to back a relocatable and
resizable resource such as the I/O window decoders in PCI-PCI bridges.
- rman_adjust_resource() can adjust the start and end address of an
existing resource. It only succeeds if the newly requested address
space is already free. It also supports shrinking a resource in
which case the freed space will be marked unallocated in the rman.
- rman_first_free_region() and rman_last_free_region() return the
start and end addresses for the first or last unallocated region in
an rman, respectively. This can be used to determine by how much
the resource backing an rman must be adjusted to accomodate an
allocation request that does not fit into the existing rman.
While here, document the rm_start and rm_end fields in struct rman,
rman_is_region_manager(), the bound argument to
rman_reserve_resource_bound(), and rman_init_from_resource().
FreeBSD" FreeBSD Foundation funded project.
- Add new man pages for the modular congestion control, Khelp and Hhook
frameworks (cc.4, cc.9, khelp.9 and hhook.9).
- Add new man pages for each available congestion control algorithm (cc_chd.4,
cc_cubic.4, cc_hd.4, cc_htcp.4, cc_newreno.4 and cc_vegas.4).
- Add a new man page for the Enhanced Round Trip Time (ERTT) Khelp module
(h_ertt.4).
- Update the TCP (tcp.4) man page to mention the TCP_CONGESTION socket option,
cross reference to cc.4 and remove references to the retired
"net.inet.tcp.newreno" sysctl MIB variable.
In collaboration with: David Hayes <dahayes at swin edu au> and
Grenville Armitage <garmitage at swin edu au>
Sponsored by: FreeBSD Foundation
MFC after: 3 months
reading. (This was already done for writing to a sysctl). This
requires all SYSCTL setups to specify a type. Most of them are now
checked at compile-time.
Remove SYSCTL_*X* sysctl additions as the print being in hex should be
controlled by the -x flag to sysctl(8).
Succested by: bde
Although not directly related the FreeBSD Foundation funded "Five New TCP
Congestion Control Algorithms for FreeBSD" project, the understanding and
inspiration required to write this documentation was significantly bolstered
by the Foundation's support.
Reviewed by: pjd
MFC after: 1 week
svn r147332 (by jeff): "Don't make vgonel() globally visible".
While here, specify the vnode locking scheme for vgone().
Discussed on: freebsd-hackers@
Approved by: kib (mentor)
MFC after: 10 days
code associated with overflow or with the drain function. While this
function is not expected to be used often, it produces more information
in the form of an errno that sbuf_overflowed() did.
called when the sbuf internal buffer is filled. For kernel sbufs with a
drain, the internal buffer will never be expanded. For userland sbufs
with a drain, the internal buffer may still be expanded by
sbuf_[v]printf(3).
Sbufs now have three basic uses:
1) static string manipulation. Overflow is marked.
2) dynamic string manipulation. Overflow triggers string growth.
3) drained string manipulation. Overflow triggers draining.
In all cases the manipulation is 'safe' in that overflow is detected and
managed.
Reviewed by: phk (the previous version)
- add rm_try_rlock().
- add RM_SLEEPABLE to use sx(9) as the back-end lock in order to sleep while
holding the write lock.
- change rm_noreadtoken to a cpu bitmask to indicate which CPUs need to go
through the lock/unlock in order to synchronize. As a side effect, this
also avoids IPI to CPUs without any readers during rm_wlock.
Discussed with: ups@, rwatson@ on arch@
Sponsored by: Isilon Systems, Inc.
- chooseproc() is long gone, MLINK choosethread instead
- Update NAME section for choosethread
- Mark chooseproc.9 for removal
PR: 149549
Submitted by: pluknet
MFC after: 1 week
