hwpmc: Implement per-thread counters for PMC sampling

This implements per-thread counters for PMC sampling. The thread
descriptors are stored in a list attached to the process descriptor.
These thre

hwpmc: Implement per-thread counters for PMC sampling

This implements per-thread counters for PMC sampling. The thread
descriptors are stored in a list attached to the process descriptor.
These thread descriptors can store any per-thread information necessary
for current or future features. For the moment, they just store the counters
for sampling.

The thread descriptors are created when the process descriptor is created.
Additionally, thread descriptors are created or freed when threads
are started or stopped. Because the thread exit function is called in a
critical section, we can't directly free the thread descriptors. Hence,
they are freed to a cache, which is also used as a source of allocations
when needed for new threads.

Approved by: sbruno
Obtained from: jtl
Sponsored by: Juniper Networks, Limelight Networks
Differential Revision: https://reviews.freebsd.org/D15335

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Add PROC_PDEATHSIG_SET to procctl interface.

Allow processes to request the delivery of a signal upon death of
their parent process. Supposed consumer of the feature is PostgreSQL.

Submitted by: T

Add PROC_PDEATHSIG_SET to procctl interface.

Allow processes to request the delivery of a signal upon death of
their parent process. Supposed consumer of the feature is PostgreSQL.

Submitted by: Thomas Munro
Reviewed by: jilles, mjg
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D15106

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Account the size of the vslock-ed memory by the thread.
Assert that all such memory is unwired on return to usermode.

The count of the wired memory will be used to detect the copyout mode.

Tested b

Account the size of the vslock-ed memory by the thread.
Assert that all such memory is unwired on return to usermode.

The count of the wired memory will be used to detect the copyout mode.

Tested by: pho (as part of the larger patch)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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Merge ^/head r327886 through r327930.

Implement 'domainset', a cpuset based NUMA policy mechanism. This allows
userspace to control NUMA policy administratively and programmatically.

Implement domainset based iterators in the page laye

Implement 'domainset', a cpuset based NUMA policy mechanism. This allows
userspace to control NUMA policy administratively and programmatically.

Implement domainset based iterators in the page layer.

Remove the now legacy numa_* syscalls.

Cleanup some header polution created by having seq.h in proc.h.

Reviewed by: markj, kib
Discussed with: alc
Tested by: pho
Sponsored by: Netflix, Dell/EMC Isilon
Differential Revision: https://reviews.freebsd.org/D13403

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sys/kern: adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone

sys/kern: adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

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Merge ^/head r325505 through r325662.

Introduce EVENTHANDLER_LIST and some users.

This introduces a facility to EVENTHANDLER(9) for explicitly defining a
reference to an event handler list. This is useful since previously all
invokers o

Introduce EVENTHANDLER_LIST and some users.

This introduces a facility to EVENTHANDLER(9) for explicitly defining a
reference to an event handler list. This is useful since previously all
invokers of events had to do a locked traversal of the global list of
event handler lists in order to find the appropriate event handler list.
By keeping a pointer to the appropriate list an invoker can avoid this
traversal completely. The pointer is initialized with SYSINIT(9) during
the eventhandler stage. Users registering interest in events do not need
to know if the event is backed by such a list, since the list is added
to the global list of lists. As with lists that are not pre-defined it
is safe to register for the events before the list has been created.

This converts the process_* and thread_* events to using the new
facility, as these are events whose locked traversals end up showing up
significantly in ports build workflows (and presumably other workflows
with many short lived threads/procs). It may be advantageous to convert
other events to using the new facility.

The el_flags field is now unused, but leave it be so that this revision
can be MFC'd.

Reviewed by: bdrewery, markj, mjg
Approved by: rstone (mentor)
In collaboration with: ian
MFC after: 4 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D12814

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Merge ^/head r319801 through r320041.

Move struct syscall_args syscall arguments parameters container into
struct thread.

For all architectures, the syscall trap handlers have to allocate the
structure on the stack. The structure takes

Move struct syscall_args syscall arguments parameters container into
struct thread.

For all architectures, the syscall trap handlers have to allocate the
structure on the stack. The structure takes 88 bytes on 64bit arches
which is not negligible. Also, it cannot be easily found by other
code, which e.g. caused duplication of some members of the structure
to struct thread already. The change removes td_dbg_sc_code and
td_dbg_sc_nargs which were directly copied from syscall_args.

The structure is put into the copied on fork part of the struct thread
to make the syscall arguments information correct in the child after
fork.

This move will also allow several more uses shortly.

Reviewed by: jhb (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
X-Differential revision: https://reviews.freebsd.org/D11080

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Merge ^/head r317503 through r317807.

Add asserts to verify stability of struct proc and struct thread layouts.

Some notes:
- Only i386 and amd64 layouts are checked, other Tier-1 (or close to
it) architectures would benefit from the

Add asserts to verify stability of struct proc and struct thread layouts.

Some notes:
- Only i386 and amd64 layouts are checked, other Tier-1 (or close to
it) architectures would benefit from the same check.
- Unconditional enabling of the asserts depend on the stability of locks
memory layout. If locks are optimized to avoid bloat when some debugging
or profiling features turned off, it makes sense to only assert layout
for production configs.

Reviewed by: badger, emaste, jhb, vangyzen
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D10526

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Merge ^/head r316992 through r317215.

- Remove 'struct vmmeter' from 'struct pcpu', leaving only global vmmeter
in place. To do per-cpu stats, convert all fields that previously were
maintained in the vmmeters that sit in pcpus to c

- Remove 'struct vmmeter' from 'struct pcpu', leaving only global vmmeter
in place. To do per-cpu stats, convert all fields that previously were
maintained in the vmmeters that sit in pcpus to counter(9).
- Since some vmmeter stats may be touched at very early stages of boot,
before we have set up UMA and we can do counter_u64_alloc(), provide an
early counter mechanism:
o Leave one spare uint64_t in struct pcpu, named pc_early_dummy_counter.
o Point counter(9) fields of vmmeter to pcpu[0].pc_early_dummy_counter,
so that at early stages of boot, before counters are allocated we already
point to a counter that can be safely written to.
o For sparc64 that required a whole dummy pcpu[MAXCPU] array.

Further related changes:
- Don't include vmmeter.h into pcpu.h.
- vm.stats.vm.v_swappgsout and vm.stats.vm.v_swappgsin changed to 64-bit,
to match kernel representation.
- struct vmmeter hidden under _KERNEL, and only vmstat(1) is an exclusion.

This is based on benno@'s 4-year old patch:
https://lists.freebsd.org/pipermail/freebsd-arch/2013-July/014471.html

Reviewed by: kib, gallatin, marius, lidl
Differential Revision: https://reviews.freebsd.org/D10156

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All these files need sys/vmmeter.h, but now they got it implicitly
included via sys/pcpu.h.

actually implement proc:::lwp-exit probe

MFC after: 4 days

Merge ^/head r314178 through r314269.

Do not leak mount references for dying threads.

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 user

Do not leak mount references for dying threads.

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

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Merge ^/head r313301 through r313643.

MFhead@r313398

Bump struct thread alignment to 32.

This gives additional bits to use in locking primitives which store
the lock thread pointer in the lock value.

Discussed with: kib

Merge ^/head r303250 through r304235.

Rewrite subr_sleepqueue.c use of callouts to not depend on the
specifics of callout KPI. Esp., do not depend on the exact interface
of callout_stop(9) return values.

The main change is that instead

Rewrite subr_sleepqueue.c use of callouts to not depend on the
specifics of callout KPI. Esp., do not depend on the exact interface
of callout_stop(9) return values.

The main change is that instead of requiring precise callouts, code
maintains absolute time to wake up. Callouts now should ensure that a
wake occurs at the requested moment, but we can tolerate both run-away
callout, and callout_stop(9) lying about running callout either way.

As consequence, it removes the constant source of the bugs where
sleepq_check_timeout() causes uninterruptible thread state where the
thread is detached from CPU, see e.g. r234952 and r296320.

Patch also removes dual meaning of the TDF_TIMEOUT flag, making code
(IMO much) simpler to reason about.

Tested by: pho
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
Differential revision: https://reviews.freebsd.org/D7137

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Provide helper macros to detect 'non-silent SBDRY' state and to
calculate appropriate return value for stops. Simplify the code by
using them.

Fix typo in sig_suspend_threads(). The thread which s

Provide helper macros to detect 'non-silent SBDRY' state and to
calculate appropriate return value for stops. Simplify the code by
using them.

Fix typo in sig_suspend_threads(). The thread which sleep must be
aborted is td2. (*)

In issignal(), when handling stopping signal for thread in
TD_SBDRY_INTR state, do not stop, this is wrong and fires assert.
This is yet another place where execution should be forced out of
SBDRY-protected region. For such case, return -1 from issignal() and
translate it to corresponding error code in sleepq_catch_signals().
Assert that other consumers of cursig() are not affected by the new
return value. (*)

Micro-optimize, mostly VFS and VOP methods, by avoiding calling the
functions when SIGDEFERSTOP_NOP non-change is requested. (**)

Reported and tested by: pho (*)
Requested by: bde (**)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Approved by: re (gjb)

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Rewrite sigdeferstop(9) and sigallowstop(9) into more flexible
framework allowing to set the suspension policy for the dynamic block.
Extend the currently possible policies of stopping on interruptib

Rewrite sigdeferstop(9) and sigallowstop(9) into more flexible
framework allowing to set the suspension policy for the dynamic block.
Extend the currently possible policies of stopping on interruptible
sleeps and ignoring such sleeps by two more: do not suspend at
interruptible sleeps, but interrupt them with either EINTR or ERESTART.

Reviewed by: jilles
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Approved by: re (gjb)

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