proc: Remove kernel stack swapping support, part 6

- Remove most checks of the P_INMEM flag.
- Some uses remain since a few userspace tools, e.g., ps(1) and top(1)
expect the flag to be set. Thes

proc: Remove kernel stack swapping support, part 6

- Remove most checks of the P_INMEM flag.
- Some uses remain since a few userspace tools, e.g., ps(1) and top(1)
expect the flag to be set. These can be cleaned up but the code has
most likely been copy-pasted elsewhere and while linger for a long
time.

Tested by: pho
Reviewed by: alc, imp, kib
Differential Revision: https://reviews.freebsd.org/D46117

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thread: Remove kernel stack swapping support, part 4

- Remove the IS_SWAPPED thread inhibitor state.
- Remove all uses of TD_IS_SWAPPED() in the kernel.
- Remove the TDF_CANSWAP flag.
- Remove the P

thread: Remove kernel stack swapping support, part 4

- Remove the IS_SWAPPED thread inhibitor state.
- Remove all uses of TD_IS_SWAPPED() in the kernel.
- Remove the TDF_CANSWAP flag.
- Remove the P_SWAPPINGOUT and P_SWAPPINGIN flags.

Tested by: pho
Reviewed by: alc, imp, kib
Differential Revision: https://reviews.freebsd.org/D46115

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sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

Move kstack_contains() and GET_STACK_USAGE() to MD machine/stack.h

Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D38320

Use atomic loads/stores when updating td->td_state

KCSAN complains about racy accesses in the locking code. Those races are
fine since they are inside a TD_SET_RUNNING() loop that expects the value

Use atomic loads/stores when updating td->td_state

KCSAN complains about racy accesses in the locking code. Those races are
fine since they are inside a TD_SET_RUNNING() loop that expects the value
to be changed by another CPU.

Use relaxed atomic stores/loads to indicate that this variable can be
written/read by multiple CPUs at the same time. This will also prevent
the compiler from doing unexpected re-ordering.

Reported by: GENERIC-KCSAN
Test Plan: KCSAN no longer complains, kernel still runs fine.
Reviewed By: markj, mjg (earlier version)
Differential Revision: https://reviews.freebsd.org/D28569

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ddb: Display process flags (p_flag and p_flag2) in 'show proc'.

Reviewed by: kib
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D27872

Use kdb_thr_* to iterate over threads consistently in DDB.

The "findstack", "show all trace", and "show active trace" commands
were iterating over allproc to enumerate threads. This missed threads

Use kdb_thr_* to iterate over threads consistently in DDB.

The "findstack", "show all trace", and "show active trace" commands
were iterating over allproc to enumerate threads. This missed threads
executing in exit1() after being removed from allproc.

Reviewed by: kib
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D27829

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ddb ps: Use the pidhash to enumerate processes not in allproc.

Exiting processes that have been removed from allproc but are still
executing are not yet marked PRS_ZOMBIE, so they were not listed (f

ddb ps: Use the pidhash to enumerate processes not in allproc.

Exiting processes that have been removed from allproc but are still
executing are not yet marked PRS_ZOMBIE, so they were not listed (for
example, if a thread panics during exit1()). To detect these
processes, clear p_list.le_prev to NULL explicitly after removing a
process from the allproc list and check for this sentinel rather than
PRS_ZOMBIE when walking the pidhash.

While here, simplify the pidhash walk to use a single outer loop.

Reviewed by: kib
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D27824

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Add a kstack_contains() helper function.

This is useful for stack unwinders which need to avoid out-of-bounds
reads of a kernel stack which can trigger kernel faults.

Reviewed by: kib, markj
Obtain

Add a kstack_contains() helper function.

This is useful for stack unwinders which need to avoid out-of-bounds
reads of a kernel stack which can trigger kernel faults.

Reviewed by: kib, markj
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D27356

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ddb: clean up empty lines in .c and .h files

sleep(9), sleepqueue(9): const'ify wchan pointers

_sleep(9), wakeup(9), sleepqueue(9), et al do not dereference or modify the
channel pointers provided in any way; they are merely used as intptrs in

sleep(9), sleepqueue(9): const'ify wchan pointers

_sleep(9), wakeup(9), sleepqueue(9), et al do not dereference or modify the
channel pointers provided in any way; they are merely used as intptrs into a
dictionary structure to match waiters with wakers. Correctly annotate this
such that _sleep() and wakeup() may be used on const pointers without
invoking ugly patterns like __DECONST(). Plumb const through all of the
underlying sleepqueue bits.

No functional change.

Reviewed by: rlibby
Discussed with: kib, markj
Differential Revision: https://reviews.freebsd.org/D22914

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Merge ^/head r351317 through r351731.

proc: eliminate the zombproc list

It is not needed by anything in the kernel and it slightly drives up contention
on both proctree and allproc locks.

Reviewed by: kib
Sponsored by: The FreeBSD Foun

proc: eliminate the zombproc list

It is not needed by anything in the kernel and it slightly drives up contention
on both proctree and allproc locks.

Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21447

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Cache kernel stacks in UMA. This gives us NUMA support, better concurrency,
and more statistics.

Reviewed by: kib, markj
Tested by: pho
Sponsored by: Netflix
Differential Revision: https://reviews.

Cache kernel stacks in UMA. This gives us NUMA support, better concurrency,
and more statistics.

Reviewed by: kib, markj
Tested by: pho
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D20931

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MFHead @349476

Sponsored by: The FreeBSD Foundation

ddb show proc typo

MFHead @348740

Sponsored by: The FreeBSD Foundation

db show thread: avoid overflow in tick conversion

The previous calculations for displaying the time since last switch
easily overflowed, after less than 36 min for hz=1000. Now overflow
takes 2000

db show thread: avoid overflow in tick conversion

The previous calculations for displaying the time since last switch
easily overflowed, after less than 36 min for hz=1000. Now overflow
takes 2000 times longer (as long as ticks takes to wrap).

Reviewed by: cem, markj
Sponsored by: Dell EMC Isilon
Differential revision: https://reviews.freebsd.org/D20273

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Merge ^/head r343807 through r343955.

ddb: Print the thread's pcb in 'show thread'

This can aid with debugging when a thread is running and has no backtrace.
State can be estimated based on the pcb, and refined from there, for
example,

ddb: Print the thread's pcb in 'show thread'

This can aid with debugging when a thread is running and has no backtrace.
State can be estimated based on the pcb, and refined from there, for
example, to get a rough idea of the stack pointer.

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MFH @ r337607, in preparation for boarding

Merge ^/head r337286 through r337585.

add an option for ddb ps command to print process arguments

We use ps to collect the information of all processes in textdump. But
it doesn't contain process arguments which however sometimes are ve

add an option for ddb ps command to print process arguments

We use ps to collect the information of all processes in textdump. But
it doesn't contain process arguments which however sometimes are very
useful for debugging. The new 'a' modifier adds that capability.

While here, remove 'm' modifier from ddb.4. It was in the manual page
from its very first revision, but I could not find any evidence of the
code ever supporting it.

Submitted by: Terry Hu <thu@panzura.com>
Reviewed by: kib
MFC after: 1 week
Sponsored by: Panzura
Differential Revision: https://reviews.freebsd.org/D16603

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Extend show proc with reaper, sigparent, and vmspace information
I have regularly needed the last couple of months.

Sponsored by: iXsystems, Inc.

Merge ^/head r325999 through r326131.