32 bits. Some times compiler inserts unnecessary instructions to preserve
unused upper 32 bits even when it is casted to a 32-bit value. It reduces
such compiler mistakes where every cycle counts.
MPERF MSRs are available. It was disabled in r216443. Remove the earlier
hack to subtract 0.5% from the calibrated frequency as DELAY(9) is little
bit more reliable now.
safer for i386 because it can be easily over 4 GHz now. More worse, it can
be easily changed by user with 'machdep.tsc_freq' tunable (directly) or
cpufreq(4) (indirectly). Note it is intentionally not used in performance
critical paths to avoid performance regression (but we should, in theory).
Alternatively, we may add "virtual TSC" with lower frequency if maximum
frequency overflows 32 bits (and ignore possible incoherency as we do now).
functions are implemented with CMPXCHG8B instruction where it is available,
i. e., all Pentium-class and later processors. Note this instruction is
also used for atomic_store_rel_64() because a simple XCHG-like instruction
for 64-bit memory access does not exist, unfortunately. If the processor
lacks the instruction, i. e., 80486-class CPUs, two 32-bit load/store are
performed with interrupt temporarily disabled, assuming it does not support
SMP. Although this assumption may be little naive, it is true in reality.
This implementation is inspired by Linux.
at run-time on i386. cpu_ticks() is set to use RDTSC early enough on i386
where it is available. Otherwise, cpu_ticks() is driven by the current
timecounter hardware as binuptime(9) does. This also avoids unnecessary
namespace pollution from <machine/cputypes.h>.
I have not properly thought through the commit. After r220031 (linux
compat: improve and fix sendmsg/recvmsg compatibility) the basic
handling for SO_PASSCRED is not sufficient as it breaks recvmsg
functionality for SCM_CREDS messages because now we would need to handle
sockcred data in addition to cmsgcred. And that is not implemented yet.
Pointyhat to: avg
Introduce the AHB glue for Atheros embedded systems. Right now it's
hard-coded for the AR9130 chip whose support isn't yet in this HAL;
it'll be added in a subsequent commit.
Kernel configuration files now need both 'ath' and 'ath_pci' devices; both
modules need to be loaded for the ath device to work.
This seems to have been a part of a bigger patch by dchagin that either
haven't been committed or committed partially.
Submitted by: dchagin, nox
MFC after: 2 weeks
And drop dummy definitions for those system calls.
This may transiently break the build.
PR: kern/149168
Submitted by: John Wehle <john@feith.com>
Reviewed by: netchild
MFC after: 2 weeks
Since signal trampolines are copied to the shared page do not need to
leave place on the stack for it. Forgotten in the previous commit.
MFC after: 1 Week
CPUs. These CPUs need explicit MSR configuration to expose ceratin CPU
capabilities (e.g., CMPXCHG8B) to work around compatibility issues with
ancient software. Unfortunately, Rise mP6 does not set the CX8 bit in CPUID
and there is no MSR to expose the feature although all mP6 processors are
capable of CMPXCHG8B according to datasheets I found from the Net. Clean up
and simplify VIA PadLock detection while I am in the neighborhood.
Also, express this new maximum as a fraction of the kernel's address
space size rather than a constant so that increasing KVA_PAGES will
automatically increase this maximum. As a side-effect of this change,
kern.maxvnodes will automatically increase by a proportional amount.
While I'm here ensure that this change doesn't result in an unintended
increase in maxpipekva on i386. Calculate maxpipekva based upon the
size of the kernel address space and the amount of physical memory
instead of the size of the kmem map. The memory backing pipes is not
allocated from the kmem map. It is allocated from its own submap of
the kernel map. In short, it has no real connection to the kmem map.
(In fact, the commit messages for the maxpipekva auto-sizing talk
about using the kernel map size, cf. r117325 and r117391, even though
the implementation actually used the kmem map size.) Although the
calculation is now done differently, the resulting value for
maxpipekva should remain almost the same on i386. However, on amd64,
the value will be reduced by 2/3. This is intentional. The recent
change to VM_KMEM_SIZE_SCALE on amd64 for the benefit of ZFS also had
the unnecessary side-effect of increasing maxpipekva. This change is
effectively restoring maxpipekva on amd64 to its prior value.
Eliminate init_param3() since it is no longer used.
configurations and make it opt-in for those who want it. LINT will
still build it.
While it may be a perfect win in some scenarios, it still troubles users
(see PRs) in general cases. In addition we are still allocating resources
even if disabled by sysctl and still leak arp/nd6 entries in case of
interface destruction.
Discussed with: qingli (2010-11-24, just never executed)
Discussed with: juli (OCTEON1)
PR: kern/148018, kern/155604, kern/144917, kern/146792
MFC after: 2 weeks
Unfortunately, it pulls in <machine/cputypes.h> but it is small enough and
namespace pollution is minimal, I hope.
Pointed out by: bde
Pointy hat: jkim
soon as possible for stack protector. However, dummy timecounter does not
have enough entropy and we don't need to sacrifice Pentium class and later.
Pointed out by: Maxim Dounin (mdounin at mdounin dot ru)
explicit process at fork trampoline path instead of eventhadler(schedtail)
invocation for each child process.
Remove eventhandler(schedtail) code and change linux ABI to use newly added
sysvec method.
While here replace explicit comparing of module sysentvec structure with the
newly created process sysentvec to detect the linux ABI.
Discussed with: kib
MFC after: 2 Week
White list sysarch calls allowed in capability mode; arguably, there
should be some link between the capability mode model and the privilege
model here. Sysarch is a morass similar to ioctl, in many senses.
Submitted by: anderson
Discussed with: benl, kris, pjd
Sponsored by: Google, Inc.
Obtained from: Capsicum Project
MFC after: 3 months
