These functions are used a lot for mutexes, so this reduces the text
size of an average kernel by about 0.75%. This wasn't intended to
be a significant optimization, but it somehow increased the maximum
number of packets per second that can be transmitted by my bge hardware
from 320000 to 460000 (this benchmark is CPU-bound and remarkably
sensitive to changes in the text section).
Details: we would prefer to leave the result of the cmpxchg in %al,
but cannot tell gcc that it is there, so we have to convert it to an
integer register. We converted to %al, then to %[re]ax, but the
latter step is usually wasted since gcc usually only wants the condition
code and can recover it from %al just as easily as from %[re]ax. Let
gcc promote %al in the few cases where this is needed.
Nearby style fixes;
- let gcc manage the load of `res', and don't abuse `res' for a copy of `exp'
- don't echo `res's name in comments
- consistently spell the condition code as 'e' after comparison for equality
- don't hard-code %al anywhere except in constraints
- for the version that doesn't use cmpxchg, there is no requirement to use
%al anywhere, so don't hard-code it in the constraints either.
Style non-fix:
- for the versions that use cmpxchg, keep using "a" (was %[re]ax, now %al)
for the main output operand, although this is not required. The input
and output operands that use the "a" constraint are now decoupled, and
this makes things clearer except for the reason that the output register
is hard-coded. It is now just a hack to tell gcc that the input "a" has
been clobbered without increasing the number of operands.
o change handling of regdomain-related mib knobs so they can be set
post-attach: regdomain, countrycode, outdoor, and xchanmode; the
hal will not permit changing the regdomain but we expose it for now
o on regdomain/countrycode change recalculate the channel list and
push it to the net80211 layer (NB: looks to need more tweaking)
o setup rate tables for half/quarter rate channels
o honor half/quarter rate channel configs when changing channels
o honor half/quarter rate channel configs when setting the slot time
o use hack/nonstandard channel numbering scheme for the public safety
band to avoid overlapping 2.4G channels on dual-band cards
o remove setup of ic_sup_rates; the net80211 layer can do this for us
and it simplifies handling of half/quarter rate channels
Tested only in Public Safety Band with cards that have RF5112.
o add hack/nonstandard channel mapping for public safety band channels to
mirror kernel (temporary until we have proper 802.11 state)
o change ieee80211_mhz2ieee to take channel flags (unused right now)
While here do some minor fixups like using IEEE80211_IS_CHAN_ANYG.
in the Public Safety Band):
o add channel flags to identify half/quarter-rate operation
o add rate sets (need to check spec on 4Mb/s in 1/4 rate)
o add if_media definitions for new rates
o split net80211 channel setup out into ieee80211_chan_init
o fixup ieee80211_mhz2ieee and ieee80211_ieee2mhz to understand half/quarter
rate channels: note we temporarily use a nonstandard/hack numbering that
avoids overlap with 2.4G channels because we don't (yet) have enough
state to identify and/or map overlapping channel sets
o fixup ieee80211_ifmedia_init so it can be called post attach and will
recalculate the channel list and associated state; this enables changing
channel-related state like the regulatory domain after attach (will be
needed for 802.11d support too)
o add ieee80211_get_suprates to return a reference to the supported rate
set for a given channel
o add 3, 4.5, and 27 MB/s tx rates to rate <-> media conversion routines
o const-poison channel arg to ieee80211_chan2mode
Document my recent changes to rc.subr(8):
- there is $required_modules now;
- $required_* are checked before invoking a custom start method, too.
MFC after: 1 month
Implement the checks for required_* objects as two functions, one
to be run before precmd and the other after it. They get the current
rc command as an argument so they can choose what requirement tests
to perform. As of now, only "start" needs such tests.
Implement a new requirement variable, required_modules. It can
list kernel modules that need to be loaded after start_precmd
indicated success. Each name in the list can be just "file", or
"file:module", or "file~regex". This will allow us to remove a lot
of duplicated code from rc.d scripts.
Perform the checks not only for the default start method, but for
any method. This allows for more flexibility and fixes a few rc.d
scripts (namely newsyslog, pf, sendmail) that rely on a required_*
variable while providing a non-default start method.
To be able to call the new check_required* functions naturally,
remove lots of crufty duplicated code pieces from run_rc_command
and replace each of them by a call to the helper function providing
a single corrected instance of the respective code snippet. Now
run_rc_command isn't as scary as it used to be, and it even appears
to have quite a nice logic that was obscured by the old crufty code.
In the default handler for restart, run start from a subshell to
protect global varibles, e.g., _postcmd, from modification by the
start handler. This enables using restart_postcmd. [x]
PR: conf/98734 [x]
Submitted by: Rick van der Zwet <rick@wzoeterwoude.net> [x]
Reviewed by: freebsd-rc (silence for an older version)
MFC after: 1 month
bge_intr(). Some of them are used in bge_poll(). Simplify by only
initializing these for polling mode and not toggling them when switching
modes. This also fixes missing synchronization with the coalescing
engine in the toggling.
- New Darwin, FreeBSD, and NetBSD versions.
- DragonFly support including the new .Dx macro.
- New .St strings: -isoC-amd1, -isoC-tcor1, -isoC-tcor2, and -ieee1275-94.
members of the ELF Executable Header inside the library-private
`struct _Elf' descriptor and only update the underlying Elf{32,64}_Ehdr
structure on an elf_update(3) call. These fields of the Ehdr
structure are technically `out of bounds' for an application program
per the ELF(3) API, but we've seen applications that initialize
a new Ehdr structure using memcpy(), messing up the library's
invariants. [1]
Implement elf_getphnum() and handle ELF objects with more than
64K program header table entries.
Reported by: jb [1]
conversion of negative numbers to always result in -1.
While at it, rearrange the nearby comment so it fits in 80 chars per line,
like the rest of this file does.
PR: 107130
MFC after: 1 day
Add a pointer to the relevant PR for future reference. The whole comment
will be OK to remove as soon as the general solution is applied.
PR: kern/105943
pmap on i386
- check for change in executable status in pmap_enter
- pmap_qenter and pmap_qremove only need to invalidate the range if one
of the pages has been referenced
- remove pmap_kenter/pmap_kremove as they were only used by pmap_qenter
and pmap_qremove
- in pmap_copy don't copy wired bit to destination pmap
- mpte was unused in pmap_enter_object - remove
- pmap_enter_quick_locked is not called on the kernel_pmap, remove check
- move pmap_remove_write specific logic out of tte_clear_phys_bit
- in pmap_protect check for removal of execute bit
- panic in the presence of a wired page in pmap_remove_all
- pmap_zero_range can call hwblkclr if offset is zero and size is PAGE_SIZE
- tte_clear_virt_bit is only used by pmap_change_wiring - thus it can be
greatly simplified
- pmap_invalidate_page need only be called in tte_clear_phys_bit if there
is a match with flags
- lock the pmap in tte_clear_phys_bit so that clearing the page bits is
atomic with invalidating the page
- these changes result in 100s reduction in buildworld from a malloc backed
disk to a malloc backed disk - ~2.5%
