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.
update_gdt_{f,g}sbase. The functions set the flag when td == curthread,
and sysarch is always called with curthread.
Reviewed by: jhb, jkim
MFC after: 1 week
Thread might be preempted after testing, which causes the flag to be
cleared. If ast was not delivered, we will do sysret with potentially
wrong fs/gs bases.
Reviewed by: jhb, jkim
MFC after: 1 week (together with r220430, r220452)
return. The ast() function may cause a context switch in which case
PCB_FULL_IRET would be set in the pcb. However, the code was not
rechecking the flag after ast() returned and would not properly restore
the FSBASE and GSBASE MSRs. To fix, recheck the PCB_FULL_IRET flag after
ast() returns.
While here, trim an instruction (and memory access) from the doreti path
and fix a typo in a comment.
MFC after: 1 week
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).
path via the sysretq instruction to return from the system call. This was
removed in 190620 and not quite fully restored in 195486. This resolves
most of the performance regression in system call microbenchmarks between
7 and 8 on amd64.
Reviewed by: kib
MFC after: 1 week
In particular:
- implement compat shims for old stat(2) variants and ogetdirentries(2);
- implement delivery of signals with ancient stack frame layout and
corresponding sigreturn(2);
- implement old getpagesize(2);
- provide a user-mode trampoline and LDT call gate for lcall $7,$0;
- port a.out image activator and connect it to the build as a module
on amd64.
The changes are hidden under COMPAT_43.
MFC after: 1 month
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.
and per-loginclass resource accounting information, to be used by the new
resource limits code. It's connected to the build, but the code that
actually calls the new functions will come later.
Sponsored by: The FreeBSD Foundation
Reviewed by: kib (earlier version)
instead of 0x100000. As a side effect, an amd64 kernel now loads at
physical address 0x200000 instead of 0x100000. This is probably for the
best because it avoids the use of a 2MB page mapping for the first 1MB of
the kernel that also spans the fixed MTRRs. However, getmemsize() still
thinks that the kernel loads at 0x100000, and so the physical memory between
0x100000 and 0x200000 is lost. Fix this problem by replacing the hard-wired
constant in getmemsize() by a symbol "kernphys" that is defined by the
linker script.
In collaboration with: kib
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.
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
This is a minor cosmetic change - the users are more likely to want to
increase (rather than decrease) default kernel stack size,
which is already 4 pages on amd64.
MFC after: 4 days
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
on processors that support 1 GB pages. Specifically, if the end of physical
memory is not aligned to a 1 GB page boundary, then map the residual
physical memory with multiple 2 MB page mappings rather than a single 1 GB
page mapping. When a 1 GB page mapping is used for this residual memory,
access to the memory is slower than when multiple 2 MB page mappings are
used. (I suspect that the reason for this slowdown is that the TLB is
actually being loaded with 4 KB page mappings for the residual memory.)
X-MFC after: r214425
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
