Reintegrate head revisions r273096-r277147

Sponsored by: The FreeBSD Foundation

Prevent live-lock and access of destroyed data in taskqueue_drain_all().

Phabric: https://reviews.freebsd.org/D1247
Reviewed by: jhb, avg
Sponsored by: Spectra Logic Corporation

sys/kern_subr_taskq

Prevent live-lock and access of destroyed data in taskqueue_drain_all().

Phabric: https://reviews.freebsd.org/D1247
Reviewed by: jhb, avg
Sponsored by: Spectra Logic Corporation

sys/kern_subr_taskqueue.c:
Modify taskqueue_drain_all() processing to use a temporary
"barrier task", rather than rely on a user task that may
be destroyed during taskqueue_drain_all()'s execution. The
barrier task is queued behind all previously queued tasks
and then has its priority elevated so that future tasks
cannot pass it in the queue.

Use a similar barrier scheme to drain threads processing
current tasks. This requires taskqueue_run_locked() to
insert and remove the taskqueue_busy object for the running
thread for every task processed.

share/man/man9/taskqueue.9:
Remove warning about live-lock issues with taskqueue_drain_all()
and indicate that it does not wait for tasks queued after
it begins processing.

show more ...

Merge head from 7/28

MFC @ r266724

An SVM update will follow this.

Document taskqueue_start_threads_pinned

Requested by: adrian
Reviewed by: adrian
Approved by: hrs (mentor)
X-MFC-with: r266629

Merge head

IFC @264767

MFH: tracking commit

Sponsored by: The FreeBSD Foundation

Merge head up to r262222 (last merge was incomplete).

update taskqueue(9) manual page

Many thanks to bjk, gjb and pluknet for improvements and suggestions.

MFC after: 5 days
Sponsored by: HybridCluster

IFC @253398

Merge fresh head.

sync from head

Extend taskqueue(9) to enable per-taskqueue callbacks.

The scope of these callbacks is primarily to support actions that affect the
taskqueue's thread environments. They are entirely optional, and

Extend taskqueue(9) to enable per-taskqueue callbacks.

The scope of these callbacks is primarily to support actions that affect the
taskqueue's thread environments. They are entirely optional, and
consequently are introduced as a new API: taskqueue_set_callback().

This interface allows the caller to specify that a taskqueue requires a
callback and optional context pointer for a given callback type.

The callback types included in this commit can be used to register a
constructor and destructor for thread-local storage using osd(9). This
allows a particular taskqueue to define that its threads require a specific
type of TLS, without the need for a specially-orchestrated task-based
mechanism for startup and shutdown in order to accomplish it.

Two callback types are supported at this point:

- TASKQUEUE_CALLBACK_TYPE_INIT, called by every thread when it starts, prior
to processing any tasks.
- TASKQUEUE_CALLBACK_TYPE_SHUTDOWN, called by every thread when it exits,
after it has processed its last task but before the taskqueue is
reclaimed.

While I'm here:

- Add two new macros, TQ_ASSERT_LOCKED and TQ_ASSERT_UNLOCKED, and use them
in appropriate locations.
- Fix taskqueue.9 to mention taskqueue_start_threads(), which is a required
interface for all consumers of taskqueue(9).

Reviewed by: kib (all), eadler (taskqueue.9), brd (taskqueue.9)
Approved by: ken (mentor)
Sponsored by: Spectra Logic
MFC after: 1 month

show more ...

IFC @247348.

Sync with HEAD.

IFC @ r244983.

Fix typo.

Submitted by: bjk
MFC after: 3 days

Document the interpretation of the negative value of ticks for
taskqueue_enqueue_timeout(9).

MFC after: 3 days

IFC @ r238370

IFC @ r236291.
Diff reductions to the enclosure driver made in r235911.

Merge head r233826 through r236168.

Typo and mdoc(7) style fixes.

PR: 168117
Submitted by: Nobuyuki Koganemaru (kogane&jp!freebsd!org)
MFC after: 3 days

MFC

IFC @ r234692

sys/amd64/include/cpufunc.h
sys/amd64/include/fpu.h
sys/amd64/amd64/fpu.c
sys/amd64/vmm/vmm.c

- Add API to allow vmm FPU state init/save/restore.

FP stuff discussed with: kib