that the 'data' pointer is already setup to point to a valid KVM buffer
or contains the copied-in data from userland as appropriate (ioctl(2)
still does this). kern_ioctl() takes care of looking up a file pointer,
implementing FIONCLEX and FIOCLEX, and calling fi_ioctl().
- Use kern_ioctl() to implement xenix_rdchk() instead of using the stackgap
and mark xenix_rdchk() MPSAFE.
ibcs2_[gs]etgroups() rather than using the stackgap. This also makes
ibcs2_[gs]etgroups() MPSAFE. Also, it cleans up one bit of weirdness in
the old setgroups() where it allocated an entire credential just so it had
a place to copy the group list into. Now setgroups just allocates a
NGROUPS_MAX array on the stack that it copies into and then passes to
kern_setgroups().
ABI as FreeBSD's poll(2) is ABI compatible. The ibcs2_poll() function
attempted to implement poll(2) using a wrapper around select(2). Besides
being somewhat ugly, it also had at least one bug in that instead of
allocating complete fdset's on the stack via the stackgap it just allocated
pointers to fdsets.
OpenBSD. This driver seems to give a small performance increase, and
should lead to better maintainability in the future.
The nForce Ethernet-specific hack in sys/i386/xbox/xbox.c is still
required, judging from dev/nfe/if_nfe.c. The condition it hacks will
almost certainly only occur on XBOX-es anyway, so it is best left there.
Approved by: imp (mentor)
to a copied-in copy of the 'union semun' and a uioseg to indicate which
memory space the 'buf' pointer of the union points to. This is then used
in linux_semctl() and svr4_sys_semctl() to eliminate use of the stackgap.
- Mark linux_ipc() and svr4_sys_semsys() MPSAFE.
from going away. mount(2) is now MPSAFE.
- Expand the scope of Giant some in unmount(2) to protect the mp structure
(or rather, to handle concurrent unmount races) from going away.
umount(2) is now MPSAFE, as well as linux_umount() and linux_oldumount().
- nmount(2) and linux_mount() were already MPSAFE.
pmap_copy() if the mapping is VM_INHERIT_SHARE. Suppose the mapping
is also wired. vmspace_fork() clears the wiring attributes in the vm
map entry but pmap_copy() copies the PG_W attribute in the PTE. I
don't think this is catastrophic. It blocks pmap_remove_pages() from
destroying the mapping and corrupts the pmap's wiring count.
This revision fixes the problem by changing pmap_copy() to clear the
PG_W attribute.
Reviewed by: tegge@
This driver was ported from OpenBSD by Shigeaki Tagashira
<shigeaki@se.hiroshima-u.ac.jp> and posted at
http://www.se.hiroshima-u.ac.jp/~shigeaki/software/freebsd-nfe.html
It was additionally cleaned up by me.
It is still a work-in-progress and thus is purposefully not in GENERIC.
And it conflicts with nve(4), so only one should be loaded.
in 1999, and there are changes to the sysctl names compared to PR,
according to that discussion. The description is in sys/conf/NOTES.
Lines in the GENERIC files are added in commented-out form.
I'll attach the test script I've used to PR.
PR: kern/14584
Submitted by: babkin
VM_ALLOC_NORMAL instead of VM_ALLOC_SYSTEM when try is TRUE. In other
words, when get_pv_entry() is permitted to fail, it no longer tries as
hard to allocate a page.
Change pmap_enter_quick_locked() to fail rather than wait if it is
unable to allocate a page table page. This prevents a race between
pmap_enter_object() and the page daemon. Specifically, an inactive
page that is a successor to the page that was given to
pmap_enter_quick_locked() might become a cache page while
pmap_enter_quick_locked() waits and later pmap_enter_object() maps
the cache page violating the invariant that cache pages are never
mapped. Similarly, change
pmap_enter_quick_locked() to call pmap_try_insert_pv_entry() rather
than pmap_insert_entry(). Generally speaking,
pmap_enter_quick_locked() is used to create speculative mappings. So,
it should not try hard to allocate memory if free memory is scarce.
Add an assertion that the object containing m_start is locked in
pmap_enter_object(). Remove a similar assertion from
pmap_enter_quick_locked() because that function no longer accesses the
containing object.
Remove a stale comment.
Reviewed by: ups@
syscalls. This way there will be a log message printed to the console
(this time for real).
Note: UNIMPL should be used for syscalls we do not implement ever, e.g.
syscalls to load linux kernel modules.
Submitted by: rdivacky
Sponsored by: Goole SoC 2006
P4 IDs: 99600, 99602
when we're about to call kdb_trap() because the latter MI
function can disable interrupts by itself now.
Pointed out by: bde
X-MFC remark: depends on kern/subr_kdb.c#1.18
Sponsored by: RiNet (Cronyx Plus LLC)
when the bit 22 is set to 1, CPUID with EAX=0 returns a maximum
value in EAX[7..0] of 3, when set to 0(default), CPUID with EAX=0
returns the number corresponding to the maximum standard function
supported. On my machine, BIOS sets the bit to 1 to make it to be
compatible with old OS, this causes dual-core Pentium-D (two
physical cores) to be identified as hyperthreading (two logical
cores) by function mp_topology().
the return address on the stack and only then "dereferences" %pc.
Therefore, in the case of a call to an invalid address, we arrive
to the trap handler with the invalid value in tf_eip. This used
to prevent db_backtrace() from assigning the most recent and interesting
frame on the stack to the right spot in the right function, from
which the invalid call was attempted.
Try to detect and work around that by recovering the return address
from the stack.
The work-around requires the fault address be passed to db_backtrace().
Smuggle it as tf_err.
MFC after: 1 month
Sponsored by: RiNet (Cronyx Plus LLC)
Now GCC likes to stick a "mov %eax, %FOO" instruction before
"addl $BAR, %esp" if the function just called returns an int,
which is a very common case in the kernel.
Sponsored by: RiNet (Cronyx Plus LLC)
an explicit comment that it's needed for the linuxolator. This is not the
case anymore. For all other architectures there was only a "KEEP THIS".
I'm (and other people too) running a COMPAT_43-less kernel since it's not
necessary anymore for the linuxolator. Roman is running such a kernel for a
for longer time. No problems so far. And I doubt other (newer than ia32
or alpha) architectures really depend on it.
This may result in a small performance increase for some workloads.
If the removal of COMPAT_43 results in a not working program, please
recompile it and all dependencies and try again before reporting a
problem.
The only place where COMPAT_43 is needed (as in: does not compile without
it) is in the (outdated/not usable since too old) svr4 code.
Note: this does not remove the COMPAT_43TTY option.
Nagging by: rdivacky
There is a race with the current locking scheme and removing
it should have no measurable performance impact.
This fixes page faults leading to panics in pmap_enter_quick_locked()
on amd64/i386.
Reviewed by: alc,jhb,peter,ps
Update of syscall.master:
o Adding of several new dummy syscalls (268-310)
o Synchronization of amd64 syscall.master with i386 one
o Auditing added to amd64 syscall.master
o Change auditing type for lstat syscall (bugfix). [1]
P4-Changes: 98672, 98674
Noticed by: rwatson [1]
Sponsored by: Google SoC 2006
Submitted by: rdivacky
I picked it up again. The scheduler is forked from ULE, but the
algorithm to detect an interactive process is almost completely
different with ULE, it comes from Linux paper "Understanding the
Linux 2.6.8.1 CPU Scheduler", although I still use same word
"score" as a priority boost in ULE scheduler.
Briefly, the scheduler has following characteristic:
1. Timesharing process's nice value is seriously respected,
timeslice and interaction detecting algorithm are based
on nice value.
2. per-cpu scheduling queue and load balancing.
3. O(1) scheduling.
4. Some cpu affinity code in wakeup path.
5. Support POSIX SCHED_FIFO and SCHED_RR.
Unlike scheduler 4BSD and ULE which using fuzzy RQ_PPQ, the scheduler
uses 256 priority queues. Unlike ULE which using pull and push, the
scheduelr uses pull method, the main reason is to let relative idle
cpu do the work, but current the whole scheduler is protected by the
big sched_lock, so the benefit is not visible, it really can be worse
than nothing because all other cpu are locked out when we are doing
balancing work, which the 4BSD scheduelr does not have this problem.
The scheduler does not support hyperthreading very well, in fact,
the scheduler does not make the difference between physical CPU and
logical CPU, this should be improved in feature. The scheduler has
priority inversion problem on MP machine, it is not good for
realtime scheduling, it can cause realtime process starving.
As a result, it seems the MySQL super-smack runs better on my
Pentium-D machine when using libthr, despite on UP or SMP kernel.
for CBUS-PNP cards there) by default, as there are no amd64 and sparc64
machines with ISA slots and which therefore could make use of this code
known to exist. For sparc64 this additionally allows to get rid of the
compat shims for in{b,w,l}()/out{b,w,l}() etc and the associated hacks.
OK'ed by: imp, peter
the arm to compile without all the extras that don't appear, at least
not in the flavors of ARM I deal with. This helps us save about 100k.
If I've botched the available devices on a platform, please let me
know and I'll correct ASAP.
not be necessary but might be helpful and at least reduce fragmentation.
* Add an assert to detect if the wakecode ever grows too big. We include
1 KB for stack, which should be more than enough also.
* Remove unnecessary initialization of static variables.
* Add comments and a bootverbose print giving the page phys address.
to 4. There is no need to be more strict at assembly time since we copy
the code anyway to a private page.
* Clear the direction flag and eflags. Probably not necessary but it won't
hurt to be safe.
* Add prefixes to all instructions to prevent any assembler mistakes.
* Remove zeroing of eax - edi. We use those registers immediately after
to transfer values to protected mode so this was pointless.
* Update comments to reflect info found during code review.
* Add hw.acpi.resume_beep tunable and sysctl, default to 0. Beeps the PC
speaker soon after waking to diagnose whether the wakeup code is even
getting run before other drivers possibly hang the system. To stop the beep,
cause another beep (i.e. keyboard bell). Submitted by takawata@, I changed
the frequency to be lower.
* Use 4096 instead of 4 byte alignment. Might be useful although doesn't
seem to be necessary.
* Remove a useless assignment to acpi_reset_video. It was overwritten by
the default sysctl value anyway.
Eliminate unnecessary, recursive acquisitions and releases of the page
queues lock by free_pv_entry() and pmap_remove_pages().
Reduce the scope of the page queues lock in pmap_remove_pages().
that it just warns the user with a printf when it misaligns a piece
of memory that was requested through a busdma tag.
Some drivers (such as mpt, and probably others) were asking for alignments
that could not be satisfied, but as far as driver operation was concerned,
that did not matter. In the theory that other drivers will fall into
this same category, we agreed that panicing or making the allocation
fail will cause more hardship than is necessary. The printf should
be sufficient motivation to get the driver glitch fixed.
POSIX (susv3) requires this, but it is unclear what should be inherited,
duplicating whole 387 stack for new thread seems to be unnecessary and
dangerous. Revert to previous code, force a new thread to be started with
clean FP state.
the high 16 bits is non-zero, fxrstor instruction will generate GP fault,
resulting kernel crash, this bug can be triggered by setcontext and
ptrace(PT_SETXMMREGS).
other timeouts could not happen while suspending, including timeouts
for things like msleep. This caused the system to hang on suspend
when the cbb was enabled, since its suspend path powered down the
socket which used a timeout to wait for it to be done.
APM now creates a thread when it is enabled, and deletes the thread
when it is disabled. This thread takes the place of the timeout by
doing its polling every ~.9s. When the thread is disabled, it will
wakeup early, otherwise it times out and polls the varius things the
old timeout polled (APM events, suspend delays, etc).
This makes my Sony VAIO 505TS suspend/resume correctly when APM is
enabled (ACPI is black listed on my 505TS).
This will likely fix other problems with the suspend path where
drivers would sleep with msleep and/or do other timeouts. Maybe
there's some special case code that would use DELAY while suspending
and msleep otherwise that can be revisited and removed.
This was also tested by glebius@, who pointed out that in the patch I
sent him, I'd forgotten apm_saver.c
MFC After: 3 weeks
lnc(4) on PC98 and i386. The ISA front-end supports the same non-PNP
network cards as lnc(4) did and additionally a couple of PNP ones.
Like lnc(4), the C-bus front-end of le(4) only supports C-NET(98)S
and is untested due to lack of such hardware, but given that's it's
based on the respective lnc(4) and not too different from the ISA
front-end it should be highly likely to work.
- Remove the descriptions of le(4), which where converted from lnc(4),
from sys/i386/conf/NOTES and sys/pc98/conf/NOTES as there's a common
one in sys/conf/NOTES.
entry to the PCI NICs section so it's in the same spot in all GENERIC
config files.
- Add a note to the description of pcn(4) informing that is has precedence
over le(4).
Remove an unnecessary check of the table's bus clock. CPUs that
support this feature export only the high/low settings via the MSR,
packed into 32 bits.
Hardware from: Centaur Technologies
MFC after: 1 week
Add back in a scheme to emulate old type major/minor numbers via hooks into
stat, linprocfs to return major/minors that Linux app's expect. Currently
only /dev/null is always registered. Drivers can register via the Linux
type shim similar to the ioctl shim but by using
linux_device_register_handler/linux_device_unregister_handler functions.
The structure is:
struct linux_device_handler {
char *bsd_driver_name;
char *linux_driver_name;
char *bsd_device_name;
char *linux_device_name;
int linux_major;
int linux_minor;
int linux_char_device;
};
Linprocfs uses this to display the major number of the driver. The
soon to be available linsysfs will use it to fill in the driver name.
Linux_stat uses it to translate the major/minor into Linux type values.
Note major numbers are dynamically assigned via passing in a -1 for
the major number so we don't need to keep track of them.
This is somewhat needed due to us switching to our devfs. MegaCli
will not run until I add in the linsysfs and mfi Linux compat changes.
Sponsored by: IronPort Systems
conformance with the mbuf and uio load routines. ENOMEM can only happen
with BUS_DMA_NOWAIT is passed in, thus the deferals are disabled. I don't
like doing this, but fixing this fixes assumptions in other important drivers,
which is a net benefit for now.
to the unused kva in the pv memory block to thread a freelist through.
This allows us to free pages that used to be used for pv entry chunks
since we can now track holes in the kva memory block.
Idea from: ups
o Properly use rman(9) to manage resources. This eliminates the
need to puc-specific hacks to rman. It also allows devinfo(8)
to be used to find out the specific assignment of resources to
serial/parallel ports.
o Compress the PCI device "database" by optimizing for the common
case and to use a procedural interface to handle the exceptions.
The procedural interface also generalizes the need to setup the
hardware (program chipsets, program clock frequencies).
o Eliminate the need for PUC_FASTINTR. Serdev devices are fast by
default and non-serdev devices are handled by the bus.
o Use the serdev I/F to collect interrupt status and to handle
interrupts across ports in priority order.
o Sync the PCI device configuration to include devices found in
NetBSD and not yet merged to FreeBSD.
o Add support for Quatech 2, 4 and 8 port UARTs.
o Add support for a couple dozen Timedia serial cards as found
in Linux.
Remove the code to dyanmically change the pv_entry limits. Go back
to a single fixed kva reservation for pv entries, like was done
before when using the uma zone. Go back to never freeing pages
back to the free pool after they are no longer used, just like
before.
This stops the lock order reversal due to aquiring the kernel map
lock while pmap was locked.
This fixes the recursive panic if invariants are enabled.
The problem was that allocating/freeing kva causes vm_map_entry
nodes to be allocated/freed. That can recurse back into pmap as
new pages are hooked up to kvm and hence all the problem.
Allocating/freeing kva indirectly allocate/frees memory.
So, by going back to a single fixed size kva block and an index,
we avoid the recursion panics and the LOR.
The problem is that now with a linear block of kva, we have no
mechanism to track holes once pages are freed. UMA has the same
problem when using custom object for a zone and a fixed reservation
of kva. Simple solutions like having a bitmap would work, but would
be very inefficient when there are hundreds of thousands of bits
in the map. A first-free pointer is similarly flawed because pages
can be freed at random and the first-free pointer would be rewinding
huge amounts. If we could allocate memory for tree strucures or
an external freelist, that would work. Except we cannot allocate/free
memory here because we cannot allocate/free address space to use
it in. Anyway, my change here reverts back to the UMA behavior of
not freeing pages for now, thereby avoiding holes in the map.
ups@ had a truely evil idea that I'll investigate. It should allow
freeing unused pages again by giving us a no-cost way to track the
holes in the kva block. But in the meantime, this should get people
booting with witness and/or invariants again.
Footnote: amd64 doesn't have this problem because of the direct map
access method. I'd done all my witness/invariants testing there. I'd
never considered that the harmless-looking kmem_alloc/kmem_free calls
would cause such a problem and it didn't show up on the boot test.
entry (PTE) have the same meaning. The exception to this rule is the
eighth bit (0x080). It is the PS bit in a PDE and the PAT bit in a
PTE. This change avoids the possibility that pmap_enter() confuses a
PAT bit with a PS bit, avoiding a panic().
Eliminate a diagnostic printf() from the i386 pmap_enter() that serves
no current purpose, i.e., I've seen no bug reports in the last two
years that are helped by this printf().
Reviewed by: jhb
(i.e. no keyboard controller present), try two other common methods for
resetting i386 machine - pci reset and port 0x92 fast reset. Only if neither
works warn user and resort to "unmap entire address space and hope for good"
hack. This makes my MacBook Pro rebooting just fine and should also help
other legacy-free hardware out there.
Also, disable interrupts unconditionally in cpu_reset_real(), since we don't
want any interference.
MFC after: 1 week
per page = effectively 12.19 bytes per pv entry after overheads).
Instead of using a shared UMA zone for 24 byte pv entries (two 8-byte tailq
nodes, a 4 byte pointer, and a 4 byte address), we allocate a page at a
time per process. This provides 336 pv entries per process (actually, per
pmap address space) and eliminates one of the 8-byte tailq entries since
we now can track per-process pv entries implicitly. The pointer to
the pmap can be eliminated by doing address arithmetic to find the metadata
on the page headers to find a single pointer shared by all 336 entries.
There is an 11-int bitmap for the freelist of those 336 entries.
This is mostly a mechanical conversion from amd64, except:
* i386 has to allocate kvm and map the pages, amd64 has them outside of kvm
* native word size is smaller, so bitmaps etc become 32 bit instead of 64
* no dump_add_page() etc stuff because they are in kvm always.
* various pmap internals tweaks because pmap uses direct map on amd64 but
on i386 it has to use sched_pin and temporary mappings.
Also, sysctl vm.pmap.pv_entry_max and vm.pmap.shpgperproc are now
dynamic sysctls. Like on amd64, i386 can now tune the pv entry limits
without a recompile or reboot.
This is important because of the following scenario. If you have a 1GB
file (262144 pages) mmap()ed into 50 processes, that requires 13 million
pv entries. At 24 bytes per pv entry, that is 314MB of ram and kvm, while
at 12 bytes it is 157MB. A 157MB saving is significant.
Test-run by: scottl (Thanks!)
caches are dangerous" to "a shared L1 data cache is dangerous". This
is a compromise between paranoia and performance: Unlike the L1 cache,
nobody has publicly demonstrated a cryptographic side channel which
exploits the L2 cache -- this is harder due to the larger size, lower
bandwidth, and greater associativity -- and prohibiting shared L2
caches turns Intel Core Duo processors into Intel Core Solo processors.
As before, the 'machdep.hyperthreading_allowed' sysctl will allow even
the L1 data cache to be shared.
Discussed with: jhb, scottl
Security: See FreeBSD-SA-05:09.htt for background material.
Major differences:
* since there is no direct map region, there is no custom uma memory
allocator to modify to include its pages in the dumps.
* Various data entries are reduced from 64 bit to 32 bit to match the
native size.
dump_add_page() and dump_drop_page() are still present in case one wants to
arrange for arbitary pages to be dumped. This is of marginal use though
because libkvm+kgdb cannot address physical memory that isn't mapped into
kvm.
create managed mappings within the clean submap. To prevent regressions,
add assertions blocking the creation of managed mappings within the clean
submap.
Reviewed by: tegge
earlier in cpu_setregs().
- If we know this CPU has a FPU via cpuid, then just assume the INT16
interface and make the npx device quiet to not clutter the dmesg. This
is true for all Pentium and later CPUs and even some of the later 486dx
CPUs.
Reviewed by: bde
Tested by: ps
MFC after: 1 week
so that we only have to do an ioapic_write() instead of an ioapic_read()
followed by an ioapic_write() every time we mask and unmask level triggered
interrupts. This cuts the execution time for these operations roughly in
half.
Profiled by: Paolo Pisati <p.pisati@oltrelinux.com>
MFC after: 1 week
PCB in which the context of stopped CPUs is stored. To access this
PCB from KDB, we introduce a new define, called KDB_STOPPEDPCB. The
definition, when present, lives in <machine/kdb.h> and abstracts
where MD code saves the context. Define KDB_STOPPEDPCB on i386,
amd64, alpha and sparc64 in accordance to previous code.
a pv entry if the number of entries is below the high water mark for pv
entries.
Use pmap_try_insert_pv_entry() in pmap_copy() instead of
pmap_insert_entry(). This avoids possible recursion on a pmap lock in
get_pv_entry().
Eliminate the explicit low-memory checks in pmap_copy(). The check that
the number of pv entries was below the high water mark was largely
ineffective because it was located in the outer loop rather than the
inner loop where pv entries were allocated. Instead of checking, we
attempt the allocation and handle the failure.
Reviewed by: tegge
Reported by: kris
MFC after: 5 days
back to using the RSDT instead. ACPI-CA already follows this same strategy
as a workaround for yet another instance of brain-damaged BIOS writers.
PR: i386/93963
Submitted by: Masayuki FUKUI <fukui.FreeBSD@fanet.net>
Specifically, on mappings with PG_G set pmap_remove() not only performs
the necessary per-page invlpg invalidations but also performs an
unnecessary invalidation of the entire set of non-PG_G entries.
Reviewed by: tegge
Previously, we tried to allow this only for root. However, we were calling
suser() on the *target* process rather than the current process. This
means that if you can ptrace() a process running as root you can set a
hardware watch point in the kernel. In practice I think you probably have
to be root in order to pass the p_candebug() checks in ptrace() to attach
to a process running as root anyway. Rather than fix the suser(), I just
axed the entire idea, as I can't think of any good reason _at all_ for
userland to set hardware watch points for KVM.
MFC after: 3 days
Also thinks hardware watch points on KVM from userland are bad: bde, rwatson
In at least one benchmark this showed around a 20% performance increase.
If other workloads do benefit from having hyperthreads service interrupts,
we can always make this a loader tunable.
MFC after: 3 days
Tested by: ps
into a separate module. Accordingly, convert the option into a device
named similarly.
Note for MFC: Perhaps the option should stay in RELENG_6 for POLA reasons.
Suggested by: scottl
Reviewed by: cokane
MFC after: 5 days
- Throw out all of the logical APIC ID stuff. The Intel docs are somewhat
ambiguous, but it seems that the "flat" cluster model we are currently
using is only supported on Pentium and P6 family CPUs. The other
"hierarchy" cluster model that is supported on all Intel CPUs with
local APICs is severely underdocumented. For example, it's not clear
if the OS needs to glean the topology of the APIC hierarchy from
somewhere (neither ACPI nor MP Table include it) and setup the logical
clusters based on the physical hierarchy or not. Not only that, but on
certain Intel chipsets, even though there were 4 CPUs in a logical
cluster, all the interrupts were only sent to one CPU anyway.
- We now bind interrupts to individual CPUs using physical addressing via
the local APIC IDs. This code has also moved out of the ioapic PIC
driver and into the common interrupt source code so that it can be
shared with MSI interrupt sources since MSI is addressed to APICs the
same way that I/O APIC pins are.
- Interrupt source classes grow a new method pic_assign_cpu() to bind an
interrupt source to a specific local APIC ID.
- The SMP code now tells the interrupt code which CPUs are avaiable to
handle interrupts in a simpler and more intuitive manner. For one thing,
it means we could now choose to not route interrupts to HT cores if we
wanted to (this code is currently in place in fact, but under an #if 0
for now).
- For now we simply do static round-robin of IRQs to CPUs when the first
interrupt handler just as before, with the change that IRQs are now
bound to individual CPUs rather than groups of up to 4 CPUs.
- Because the IRQ to CPU mapping has now been moved up a layer, it would
be easier to manage this mapping from higher levels. For example, we
could allow drivers to specify a CPU affinity map for their interrupts,
or we could allow a userland tool to bind IRQs to specific CPUs.
The MFC is tentative, but I want to see if this fixes problems some folks
had with UP APIC kernels on 6.0 on SMP machines (an SMP kernel would work
fine, but a UP APIC kernel (such as GENERIC in RELENG_6) would lose
interrupts).
MFC after: 1 week
- Reorder the events in exit(2) slightly so that we trigger the S_EXIT
stop event earlier. After we have signalled that, we set P_WEXIT and
then wait for any processes with a hold on the vmspace via PHOLD to
release it. PHOLD now KASSERT()'s that P_WEXIT is clear when it is
invoked, and PRELE now does a wakeup if P_WEXIT is set and p_lock drops
to zero.
- Change proc_rwmem() to require that the processing read from has its
vmspace held via PHOLD by the caller and get rid of all the junk to
screw around with the vmspace reference count as we no longer need it.
- In ptrace() and pseudofs(), treat a process with P_WEXIT set as if it
doesn't exist.
- Only do one PHOLD in kern_ptrace() now, and do it earlier so it covers
FIX_SSTEP() (since on alpha at least this can end up calling proc_rwmem()
to clear an earlier single-step simualted via a breakpoint). We only
do one to avoid races. Also, by making the EINVAL error for unknown
requests be part of the default: case in the switch, the various
switch cases can now just break out to return which removes a _lot_ of
duplicated PRELE and proc unlocks, etc. Also, it fixes at least one bug
where a LWP ptrace command could return EINVAL with the proc lock still
held.
- Changed the locking for ptrace_single_step(), ptrace_set_pc(), and
ptrace_clear_single_step() to always be called with the proc lock
held (it was a mixed bag previously). Alpha and arm have to drop
the lock while the mess around with breakpoints, but other archs
avoid extra lock release/acquires in ptrace(). I did have to fix a
couple of other consumers in kern_kse and a few other places to
hold the proc lock and PHOLD.
Tested by: ps (1 mostly, but some bits of 2-4 as well)
MFC after: 1 week
Keep accounting time (in per-cpu) cputicks and the statistics counts
in the thread and summarize into struct proc when at context switch.
Don't reach across CPUs in calcru().
Add code to calibrate the top speed of cpu_tickrate() for variable
cpu_tick hardware (like TSC on power managed machines).
Don't enforce monotonicity (at least for now) in calcru. While the
calibrated cpu_tickrate ramps up it may not be true.
Use 27MHz counter on i386/Geode.
Use TSC on amd64 & i386 if present.
Use tick counter on sparc64
it. The former code used to hang older Intel CPUs by trying to get
non-existent TLB info 2^32 times.
Reduce code duplication around the calls to CPUID 0x02 by using
do-while loops.
PR: i386/92977
Tested by: cy
Rename struct thread's td_sticks to td_pticks, we will need the
other name for more appropriately named use shortly. Reduce it
from uint64_t to u_int.
Clear td_pticks whenever we enter the kernel instead of recording
its value as reference for userret(). Use the absolute value of
td->pticks in userret() and eliminate third argument.
Keep track of time spent by the cpu in various contexts in units of
"cputicks" and scale to real-world microsec^H^H^H^H^H^H^H^Hclock_t
only when somebody wants to inspect the numbers.
For now "cputicks" are still derived from the current timecounter
and therefore things should by definition remain sensible also on
SMP machines. (The main reason for this first milestone commit is
to verify that hypothesis.)
On slower machines, the avoided multiplications to normalize timestams
at every context switch, comes out as a 5-7% better score on the
unixbench/context1 microbenchmark. On more modern hardware no change
in performance is seen.
the callers if the exec either succeeds or fails early.
- Move the code to call exit1() if the exec fails after the vmspace is
gone to the bottom of kern_execve() to cut down on some code duplication.
