header. This will help to correlate console server logs with dump files,
no matter how precise is clock on a console server appliance, and how
buggy the appliance is.
This KPI explicitely indicates the intent of creating the mapping at
the fixed address, and incorporates the map locking into the callee.
Suggested and reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
all the clocks that they provide.
Each clocks are exported under the node 'clock.<clkname>' and have the following
children nodes :
- frequency
- parent (The selected parent, if any)
- parents (The list of parents, if any)
- childrens (The list of childrens, if any)
- enable_cnt (The enabled counter)
This give us the possibility to examine clocks at runtime and make graph of
the clock flow.
Reviewed by: mmel
MFC after: 2 month
Differential Revision: https://reviews.freebsd.org/D9833
We may fail to reset the %CPU tracking window if a thread does not run
for over half of the ticks rollover period, resulting in a bogus %CPU
value for the thread until ticks fully rolls over. Handle this by comparing
the unsigned difference ticks - ts_ltick with SCHED_TICK_TARG instead.
Reviewed by: cem, jeff
MFC after: 1 week
Sponsored by: Dell EMC Isilon
Elf_map_insert() needs to create mapping at the known fixed address.
Usage of vm_map_find() assumes, on the other hand, that any suitable
address space range above or equal the specified hint, is acceptable.
Due to operating on the fresh or cleared address space, vm_map_find()
usually creates mapping starting exactly at hint.
Switch to vm_map_insert() use to clearly request fixed mapping from
the VM.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
vm_map_insert() failure, drop the vnode lock around the call to
vm_object_deallocate().
Since the deallocated object is the vm object of the vnode, we might
get the vnode lock recursion there. In fact, it is almost impossible
to make vm_map_insert() failing there on stock kernel.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Unclear how, but the locking routine for mutexes was using the *release*
barrier instead of acquire. This must have been either a copy-pasto or bad
completion.
Going through other uses of atomics shows no barriers in:
- upgrade routines (addressed in this patch)
- sections protected with turnstile locks - this should be fine as necessary
barriers are in the worst case provided by turnstile unlock
I would like to thank Mark Millard and andreast@ for reporting the problem and
testing previous patches before the issue got identified.
ps.
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Hardware provided by: IBM LTC
to stdout in the non-kernel case and to the console+log
in the kernel case. For the kernel case it hooks the
putbuf() machinery underneath printf(9) so that the buffer
is written completely atomically and without a copy into
another temporary buffer. This is useful for fixing
compound console/log messages that become broken and
interleaved when multiple threads are competing for the
console.
Reviewed by: ken, imp
Sponsored by: Netflix
Thread might create a condition for delayed SU cleanup, which creates
a reference to the mount point in td_su, but exit without returning
through userret(), e.g. when terminating due to single-threading or
process exit. In this case, td_su reference is not dropped and mount
point cannot be freed.
Handle the situation by clearing td_su also in the thread destructor
and in exit1(). softdep_ast_cleanup() has to receive the thread as
argument, since e.g. thread destructor is executed in different
context.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
On Core2 and older Intel CPUs, where TSC stops in C2, system does not
allow C2 entrance if timecounter hardware is TSC. This is done by
tc_windup() which tests for TC_FLAGS_C2STOP flag of the new
timecounter and increases cpu_disable_c2_sleep if flag is set. Right
now init_TSC_tc() only sets the flag if cpu_deepest_sleep >= 2, but
TSC is initialized too early for this variable to be set by
acpi_cpu.c.
There is no reason to require that ACPI reported C2 and deeper states
to set TC_FLAGS_C2STOP, so remove cpu_deepest_sleep test from
init_TSC_tc() condition. And since this is the only use of the
variable, remove it at all.
Reported and submitted by: Jia-Shiun Li <jiashiun@gmail.com>
Suggested by: jhb
MFC after: 2 weeks
This function allows the caller to specify the reference clock
and choose between absolute and relative mode. In relative mode,
the remaining time can be returned.
The API is similar to clock_nanosleep(3). Thanks to Ed Schouten
for that suggestion.
While I'm here, reduce the sleep time in the semaphore "child"
test to greatly reduce its runtime. Also add a reasonable timeout.
Reviewed by: ed (userland)
MFC after: 2 weeks
Relnotes: yes
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D9656
data structures.
vt_change_font() calls vtbuf_grow() to change some vt driver data
structures. It uses TF_MUTE to prevent the console from trying to use those
data structures while it changes them.
During the early stage of the boot process, the vt driver's tc_done routine
uses those data structures; however, it is currently called outside the
TF_MUTE check.
Move the tc_done routine inside the locked TF_MUTE check.
PR: 217282
Reviewed by: ed, ray
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D9709
then return EAGAIN. The current code just returns that if the LAST buf
failed.
Reviewed by: kib@, trasz@
Differential Revision: https://reviews.freebsd.org/D9677
Previously, the first lines of various generated files from system call
tables were generated in two sections. Some of the initialization was
done in BEGIN, and the rest was done when the first line was encountered.
The main reason for this split before r313564 was that most of the
initialization done in the second section depended on the $FreeBSD$ tag
extracted from the system call table. Now that the $FreeBSD$ tag is no
longer used, consolidate all of the file initialization in the BEGIN
section.
This change was tested by confirming that the content of generated files
did not change.
When a thread is stopped in ptracestop(), the ptrace(2) user may request
a signal be delivered upon resumption of the thread. Heretofore, those signals
were discarded unless ptracestop()'s caller was issignal(). Fix this by
modifying ptracestop() to queue up signals requested by the ptrace user that
will be delivered when possible. Take special care when the signal is SIGKILL
(usually generated from a PT_KILL request); no new stop events should be
triggered after a PT_KILL.
Add a number of tests for the new functionality. Several tests were authored
by jhb.
PR: 212607
Reviewed by: kib
Approved by: kib (mentor)
MFC after: 2 weeks
Sponsored by: Dell EMC
In collaboration with: jhb
Differential Revision: https://reviews.freebsd.org/D9260
Right now the noexec mount option disallows image activators to try
execve the files on the mount point. Also, after r127187, noexec
also limits max_prot map entries permissions for mappings of files
from such mounts, but not the actual mapping permissions.
As result, the API behaviour is inconsistent. The files from noexec
mount can be mapped with PROT_EXEC, but if mprotect(2) drops execution
permission, it cannot be re-enabled later. Make this consistent
logically and aligned with behaviour of other systems, by disallowing
PROT_EXEC for mmap(2).
Note that this change only ensures aligned results from mmap(2) and
mprotect(2), it does not prevent actual code execution from files
coming from noexec mount. Such files can always be read into
anonymous executable memory and executed from there.
Reported by: shamaz.mazum@gmail.com
PR: 217062
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Since fcmpset can fail without lock contention e.g. on arm, it was possible
to get spurious failures when the caller was expecting the primitive to succeed.
Reported by: mmel
called for all threads belonging to a procedure. Currently the first
thread in a procedure is kept around as an optimisation step and is
never freed. Because the first thread in a procedure is never freed
nor allocated, its destructor and constructor callbacks are never
called which means per thread structures allocated by dtrace and the
Linux emulation layers for example, might be present for threads which
don't need these structures.
This patch adds a thread construction and destruction call for the
first thread in a procedure.
Tested: dtrace, linux emulation
Reviewed by: kib @
MFC after: 1 week
Sponsored by: Mellanox Technologies
Implement get_pcpu() for amd64/sparc64/mips/powerpc, and use it to
replace pcpu_find(curcpu) in MI code.
Reviewed by: andreast, kan, lidl
Tested by: lidl(mips, sparc64), andreast(powerpc)
Differential Revision: https://reviews.freebsd.org/D9587
This denotes changes which went in by accident in r313877.
On most production kernels both said parameters are zeroed and have nothing
reading them in either __mtx_lock_sleep or __mtx_unlock_sleep. Thus this change
stops passing them by internal consumers which this is the case.
Kernel modules use _flags variants which are not affected kbi-wise.
sx primitives use inlines as opposed to macros. Change the tested condition
to LOCK_DEBUG which covers the case, but is slightly overzelaous.
Reported by: kib
It is only needed if the LOCK_PROFILING is enabled. It has to always check if
the lock is about to be released which requires an avoidable read if the option
is not specified..
They all fallback to the slow path if necessary and the check is there.
This means a panicked kernel executing code from modules will be able to
succeed doing actual lock/unlock, but this was already the case for core code
which has said primitives inlined.
Something evidently got mangled in my git tree in between testing and
review, as an old and broken version of the patch was apparently submitted
to svn. Revert this while I work out what went wrong.
Reported by: tuexen
Pointy hat to: rstone
inet_ntoa() cannot be used safely in a multithreaded environment
because it uses a static local buffer. Instead, use inet_ntoa_r()
with a buffer on the caller's stack.
Suggested by: glebius, emaste
Reviewed by: gnn
MFC after: 2 weeks
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D9625
Somehow in the late stages of testing my sched_ule patch, a character was
accidentally deleted from the file. Correct this.
While I'm committing anyway, the previous commit message requires some
clarification: in the normal case of unlending priority after releasing
a mutex, the thread that was doing the lending will be woken up and
immediately become the highest-priority thread, and in that case no
priority inversion would take place. However, if that thread is pinned
to a different CPU, then the currently running thread that just had its
priority lowered will not be preempted and then priority inversion can
occur.
Reported by: O. Hartmann (typo), jhb (scheduler clarification)
MFC after: 1 month
Pointy hat to: rstone
When a high-priority thread is waiting for a mutex held by a
low-priority thread, it temporarily lends its priority to the
low-priority thread to prevent priority inversion. When the mutex
is released, the lent priority is revoked and the low-priority
thread goes back to its original priority.
When the priority of that thread is lowered (through a call to
sched_priority()), the schedule was not checking whether
there is now a high-priority thread in the run queue. This can
cause threads with real-time priority to be starved in the run
queue while the low-priority thread finishes its quantum.
Fix this by explicitly checking whether preemption is necessary
when a thread's priority is lowered.
Sponsored by: Dell EMC Isilon
Obtained from: Sandvine Inc
Differential Revision: https://reviews.freebsd.org/D9518
Reviewed by: Jeff Roberson (ule)
MFC after: 1 month
This effectively provides the same benefit as applying MADV_FREE inline
upon every execve, since the page daemon invokes lowmem handlers prior to
scanning the inactive queue. It also has less overhead; the cost of
applying MADV_FREE is very noticeable on many-CPU systems since it includes
that of a TLB shootdown of global PTEs. For instance, this change nearly
halves the system CPU usage during a buildkernel on a 128-vCPU EC2
instance (with some other patches applied).
Benchmarked by: cperciva (earlier version)
Reviewed by: kib
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D9586
Since locks are dropped when a thread suspends, it's possible for another
thread to deliver a signal to the suspended thread. If the thread awakens from
suspension without checking for signals, it may go to sleep despite having
a pending signal that should wake it up. Therefore the suspension check is
done first, so any signals sent while suspended will be caught in the
subsequent signal check.
Reviewed by: kib
Approved by: kib (mentor)
MFC after: 2 weeks
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D9530
There could be a race between the vm daemon setting RACCT_RSS based on
the vm space and vmspace_exit (called from exit1) resetting RACCT_RSS to
zero. In that case we can get a zombie process with non-zero RACCT_RSS.
If the process is jailed, that may break accounting for the jail.
There could be other consequences.
Fix this race in the vm daemon by updating RACCT_RSS only when a process
is in the normal state. Also, make accounting a little bit more
accurate by refreshing the page resident count after calling
vm_pageout_map_deactivate_pages().
Finally, add an assert that the RSS is zero when a process is reaped.
PR: 210315
Reviewed by: trasz
Differential Revision: https://reviews.freebsd.org/D9464
Rename kern_vm_* functions to kern_*. Move the prototypes to
syscallsubr.h. Also change Mach VM types to uintptr_t/size_t as
needed, to avoid headers pollution.
Requested by: alc, jhb
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D9535
