Two new functions are provided, bit_ffs_at() and bit_ffc_at(), which allow
for efficient searching of set or cleared bits starting from any bit offset
within the bit string.
Performance is improved by operating on longs instead of bytes and using
ffsl() for searches within a long. ffsl() is a compiler builtin in both
clang and gcc for most architectures, converting what was a brute force
while loop search into a couple of instructions.
All of the bitstring(3) API continues to be contained in the header file.
Some of the functions are large enough that perhaps they should be uninlined
and moved to a library, but that is beyond the scope of this commit.
sys/sys/bitstring.h:
Convert the majority of the existing bit string implementation from
macros to inline functions.
Properly protect the implementation from inadvertant macro expansion
when included in a user's program by prefixing all private
macros/functions and local variables with '_'.
Add bit_ffs_at() and bit_ffc_at(). Implement bit_ffs() and
bit_ffc() in terms of their "at" counterparts.
Provide a kernel implementation of bit_alloc(), making the full API
usable in the kernel.
Improve code documenation.
share/man/man3/bitstring.3:
Add pre-exisiting API bit_ffc() to the synopsis.
Document new APIs.
Document the initialization state of the bit strings
allocated/declared by bit_alloc() and bit_decl().
Correct documentation for bitstr_size(). The original code comments
indicate the size is in bytes, not "elements of bitstr_t". The new
implementation follows this lead. Only hastd assumed "elements"
rather than bytes and it has been corrected.
etc/mtree/BSD.tests.dist:
tests/sys/Makefile:
tests/sys/sys/Makefile:
tests/sys/sys/bitstring.c:
Add tests for all existing and new functionality.
include/bitstring.h
Include all headers needed by sys/bitstring.h
lib/libbluetooth/bluetooth.h:
usr.sbin/bluetooth/hccontrol/le.c:
Include bitstring.h instead of sys/bitstring.h.
sbin/hastd/activemap.c:
Correct usage of bitstr_size().
sys/dev/xen/blkback/blkback.c
Use new bit_alloc.
sys/kern/subr_unit.c:
Remove hard-coded assumption that sizeof(bitstr_t) is 1. Get rid of
unrb.busy, which caches the number of bits set in unrb.map. When
INVARIANTS are disabled, nothing needs to know that information.
callapse_unr can be adapted to use bit_ffs and bit_ffc instead.
Eliminating unrb.busy saves memory, simplifies the code, and
provides a slight speedup when INVARIANTS are disabled.
sys/net/flowtable.c:
Use the new kernel implementation of bit-alloc, instead of hacking
the old libc-dependent macro.
sys/sys/param.h
Update __FreeBSD_version to indicate availability of new API
Submitted by: gibbs, asomers
Reviewed by: gibbs, ngie
MFC after: 4 weeks
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D6004
It will be used for the upcoming LRO hash table initialization.
And probably will be useful in other cases, when M_WAITOK can't
be used.
Reviewed by: jhb, kib
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D6138
bus_get_cpus() returns a specified set of CPUs for a device. It accepts
an enum for the second parameter that indicates the type of cpuset to
request. Currently two valus are supported:
- LOCAL_CPUS (on x86 this returns all the CPUs in the package closest to
the device when DEVICE_NUMA is enabled)
- INTR_CPUS (like LOCAL_CPUS but only returns 1 SMT thread for each core)
For systems that do not support NUMA (or if it is not enabled in the kernel
config), LOCAL_CPUS fails with EINVAL. INTR_CPUS is mapped to 'all_cpus'
by default. The idea is that INTR_CPUS should always return a valid set.
Device drivers which want to use per-CPU interrupts should start using
INTR_CPUS instead of simply assigning interrupts to all available CPUs.
In the future we may wish to add tunables to control the policy of
INTR_CPUS (e.g. should it be local-only or global, should it ignore
SMT threads or not).
The x86 nexus driver exposes the internal set of interrupt CPUs from the
the x86 interrupt code via INTR_CPUS.
The ACPI bus driver and PCI bridge drivers use _PXM to return a suitable
LOCAL_CPUS set when _PXM exists and DEVICE_NUMA is enabled. They also and
the global INTR_CPUS set from the nexus driver with the per-domain set from
_PXM to generate a local INTR_CPUS set for child devices.
Reviewed by: wblock (manpage)
Differential Revision: https://reviews.freebsd.org/D5519
By default set to 'YES' so it does not change the current behaviour for users,
this variable allows to decide to not extract crach dumps from the dump
device at boot time by setting it to "NO" in rc.conf.
Sponsored by: Gandi.net
Specifically, mention that rman_get_bustag/handle/virtual are valid after
a resource is activated. Also, mention the wrapper API that accepts a
struct resource instead of a bus tag and handle.
The BUS_RESCAN() method rescans a single bus device checking for devices
that have been added or removed from the bus. A new 'rescan' command is
added to devctl(8) to trigger a rescan.
Differential Revision: https://reviews.freebsd.org/D6016
This is a minor follow-up to r297422, prompted by a Coverity warning. (It's
not a real defect, just a code smell.) OSD slot array reservations are an
array of pointers (void **) but were cast to void* and back unnecessarily.
Keep the correct type from reservation to use.
osd.9 is updated to match, along with a few trivial igor fixes.
Reported by: Coverity
CID: 1353811
Sponsored by: EMC / Isilon Storage Division
The mfi(4) manpage doesn't explain the modules yet, but at least we direct
users to the right place.
PR: 205925
Submitted by: dvl
MFC after: 1 week
Sponsored by: Essen Hackathon 2016
ufs/ffs/fs.h and not 10%. The newfs(8) and tunefs(8)
man pages had this change already, but fs(5) did not.
This change makes it consistent again.
Bump Dd.
PR: 204929
Submitted by: amutu@amutu.com
MFC after: 3 days
Sponsored by: Essen Linuxhotel Hackathon 2016
When using meta mode with filemon, the build is reliably incremental
safe. Bmake will use the meta files, along with filemon information,
to rebuild targets when their dependencies change, commands change,
or files they generate are missing.
Sponsored by: EMC / Isilon Storage Division
This corrects an error in r296947 in that it is not possible to assert
which thread holds a shared (or read) lock, but it is possible to assert
that one is held. Just not very useful.
MFC after: 1 week
Submitted by: wblock, jhb
Reviewed by: kib (earlier version), jhb, wblock
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D5659
sounds like some kind of horrific theme park. "Hey kids, want to go to
User Land?" "No! We'll be good!"
The obvious replacement is "userland", a compound word replete with
term-of-art meaning and just a hint of cautionary tale. The alternate
terms "flugelhorn" and "bullfrog", while also good, are less well-known
and were voted down in committee.
MFC after: 1 week
Skip the log entry as there is nothing good to write out. Don't fail
the syscall though since it already succeeded. There's no reason
filemon's tracing failure should fail the already-succeeded syscall.
Record the error for later to return from close(2) on the filemon devfs
file descriptor.
Discussed with: markj, sjg, kib (briefly with kib)
Reported by: mjg
MFC after: 2 weeks
Sponsored by: EMC / Isilon Storage Division
None of lstat(2), fstat(2), fstatat(2) were tracked either.
The other filemon implementations also do not track stat(2), nor
does bmake utilize it. The act of opening a file for read should
be enough to decide that a file is a dependency. There could be
rare cases where just having a file would cause a dependency but it
is unlikely.
MFC after: 2 weeks
Also noted by: sjg
Sponsored by: EMC / Isilon Storage Division
- proc.p_filemon is added which is protected by PROC_LOCK. This improves
performance and avoids double-fork issues, taking allproc_lock
while in syscalls, and walking the process tree in syscalls. A
particular proc.p_filemon can only be changed to NULL or another
filemon, or the filemon inherited, while the filemon->lock is held.
- Filemon are reference counted. On the last reference the log will be closed.
- When closing the devfs file handle, the filemon will be detached from all
processes and inheritance prevented.
- Disallow attaching to a process already being traced since filemon is
typically intended to be used on children only. This is allowed for
curproc as bmake relies on this behavior for rare cases when combining
.MAKE with .META.
- Detach any previously tracked process on ioctl(FILEMON_SET_PID).
- Handle error from devfs_set_cdevpriv() in filemon_open().
- The global filemon lock and lists are removed.
- A free list is no longer kept. Previously this list was
forever-expanding and never garbage cleaned.
- No longer loses track of double-forks. If the process holding the filemon
handle closes it will close the log rather than wait on a daemonized process,
but it will log all activity until it closes its handle. The filemon
will be removed from the process and not inherited.
- A separate process count is kept only as an optimization for
forced detachment to avoid taking allproc_lock and walking the entire
process tree.
- struct filemon access is protected by sx(9) filemon->lock as it was before.
- Add more comments and KASSERTS.
MFC after: 2 weeks
Reviewed by: kib, mjg, markj (all on previous versions)
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D5520
