Get rid of sa->narg. It serves no purpose; use sa->callp->sy_narg instead.

Reviewed by: kib
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26458

MFH

Sponsored by: Rubicon Communications, LLC (netgate.com)

Merge ^/head r363739 through r363986.

cred: add more asserts for td_realucred == td_ucred

MFH

Sponsored by: Rubicon Communications, LLC (netgate.com)

Short-circuit tdfind when looking for the calling thread.

Common occurence with cpuset and other places.

cred: distribute reference count per thread

This avoids dirtying creds in the common case, see the comment in kern_prot.c
for details.

Reviewed by: kib
Differential Revision: https://reviews.freebs

cred: distribute reference count per thread

This avoids dirtying creds in the common case, see the comment in kern_prot.c
for details.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D24007

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Fix up i386 thread structure layout assertions after r360354.

Reported by: Jenkins

Use a single VM object for kernel stacks.

Previously we allocated a separate VM object for each kernel stack.
However, fully constructed kernel stacks are cached by UMA, so there is
no harm in using

Use a single VM object for kernel stacks.

Previously we allocated a separate VM object for each kernel stack.
However, fully constructed kernel stacks are cached by UMA, so there is
no harm in using a single global object for all stacks. This reduces
memory consumption and makes it easier to define a memory allocation
policy for kernel stack pages, with the aim of reducing physical memory
fragmentation.

Add a global kstack_object, and use the stack KVA address to index into
the object like we do with kernel_object.

Reviewed by: kib
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D24473

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Remove the old NFS lock device driver that uses Giant.

This NFS lock device driver was replaced by the kernel NLM around FreeBSD7 and
has not normally been used since then.
To use it, the kernel had

Remove the old NFS lock device driver that uses Giant.

This NFS lock device driver was replaced by the kernel NLM around FreeBSD7 and
has not normally been used since then.
To use it, the kernel had to be built without "options NFSLOCKD" and
the nfslockd.ko had to be deleted as well.
Since it uses Giant and is no longer used, this patch removes it.

With this device driver removed, there is now a lot of unused code
in the userland rpc.lockd. That will be removed on a future commit.

Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D22933

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Retire procfs-based process debugging.

Modern debuggers and process tracers use ptrace() rather than procfs
for debugging. ptrace() has a supserset of functionality available
via procfs and new deb

Retire procfs-based process debugging.

Modern debuggers and process tracers use ptrace() rather than procfs
for debugging. ptrace() has a supserset of functionality available
via procfs and new debugging features are only added to ptrace().
While the two debugging services share some fields in struct proc,
they each use dedicated fields and separate code. This results in
extra complexity to support a feature that hasn't been enabled in the
default install for several years.

PR: 244939 (exp-run)
Reviewed by: kib, mjg (earlier version)
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D23837

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Merge ^/head r358466 through r358677.

Ensure that arm64 thread structures are allocated from the direct map.

Otherwise we can fail to handle translation faults on curthread, leading
to a panic.

Reviewed by: alc, rlibby
Sponsored by: Th

Ensure that arm64 thread structures are allocated from the direct map.

Otherwise we can fail to handle translation faults on curthread, leading
to a panic.

Reviewed by: alc, rlibby
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23895

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Merge ^/head r358239 through r358262.

Add td_pflags2, yet another thread-private flags word.

There is no more free bits in td_pflags.

Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Merge ^/head r357662 through r357854.

Add a way to manage thread signal mask using shared word, instead of syscall.

A new syscall sigfastblock(2) is added which registers a uint32_t
variable as containing the count of blocks for signal

Add a way to manage thread signal mask using shared word, instead of syscall.

A new syscall sigfastblock(2) is added which registers a uint32_t
variable as containing the count of blocks for signal delivery. Its
content is read by kernel on each syscall entry and on AST processing,
non-zero count of blocks is interpreted same as the signal mask
blocking all signals.

The biggest downside of the feature that I see is that memory
corruption that affects the registered fast sigblock location, would
cause quite strange application misbehavior. For instance, the process
would be immune to ^C (but killable by SIGKILL).

With consumers (rtld and libthr added), benchmarks do not show a
slow-down of the syscalls in micro-measurements, and macro benchmarks
like buildworld do not demonstrate a difference. Part of the reason is
that buildworld time is dominated by compiler, and clang already links
to libthr. On the other hand, small utilities typically used by shell
scripts have the total number of syscalls cut by half.

The syscall is not exported from the stable libc version namespace on
purpose. It is intended to be used only by our C runtime
implementation internals.

Tested by: pho
Disscussed with: cem, emaste, jilles
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D12773

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Correct the function name in the comment.

Sponsored by: The FreeBSD Foundation
MFC after: 3 days

vfs: prealloc vnodes in getnewvnode_reserve

Having a reserved vnode count does not guarantee that getnewvnodes wont
block later. Said blocking partially defeats the purpose of reserving in
the first

vfs: prealloc vnodes in getnewvnode_reserve

Having a reserved vnode count does not guarantee that getnewvnodes wont
block later. Said blocking partially defeats the purpose of reserving in
the first place.

Preallocate instaed. The only consumer was always passing "1" as count
and never nesting reservations.

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Rename umtxq_check_susp() to thread_check_susp()

and make it usable outside of kern_umtx.c. To be used in several
future changes.

Discussed with: markj
Sponsored by: The FreeBSD Foundation
MFC aft

Rename umtxq_check_susp() to thread_check_susp()

and make it usable outside of kern_umtx.c. To be used in several
future changes.

Discussed with: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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schedlock 4/4

Don't hold the scheduler lock while doing context switches. Instead we
unlock after selecting the new thread and switch within a spinlock
section leaving interrupts and preemption dis

schedlock 4/4

Don't hold the scheduler lock while doing context switches. Instead we
unlock after selecting the new thread and switch within a spinlock
section leaving interrupts and preemption disabled to prevent local
concurrency. This means that mi_switch() is entered with the thread
locked but returns without. This dramatically simplifies scheduler
locking because we will not hold the schedlock while spinning on
blocked lock in switch.

This change has not been made to 4BSD but in principle it would be
more straightforward.

Discussed with: markj
Reviewed by: kib
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D22778

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schedlock 1/4

Eliminate recursion from most thread_lock consumers. Return from
sched_add() without the thread_lock held. This eliminates unnecessary
atomics and lock word loads as well as reducing

schedlock 1/4

Eliminate recursion from most thread_lock consumers. Return from
sched_add() without the thread_lock held. This eliminates unnecessary
atomics and lock word loads as well as reducing the hold time for
scheduler locks. This will eventually allow for lockless remote adds.

Discussed with: kib
Reviewed by: jhb
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D22626

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amd64: move pcb out of kstack to struct thread.

This saves 320 bytes of the precious stack space.

The only negative aspect of the change I can think of is that the
struct thread increased by 320 by

amd64: move pcb out of kstack to struct thread.

This saves 320 bytes of the precious stack space.

The only negative aspect of the change I can think of is that the
struct thread increased by 320 bytes obviously, and that 320 bytes are
not swapped out anymore. I believe the freed stack space is much more
important than that. Also, current struct thread size is 1392 bytes
on amd64, so UMA will allocate two thread structures per (4KB) slab,
which leaves a space for pcb without increasing zone memory use.

Reviewed by: alc, markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D22138

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Remove epoch tracker from struct thread. It was an ugly crutch to emulate
locking semantics for if_addr_rlock() and if_maddr_rlock().

Since EPOCH_TRACE had been moved to opt_global.h, we don't need to waste
extra space in struct thread.