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Code Issues Releases Activity

Add facility to stop all userspace processes. The supposed use of the

Browse Source 
feature is to quisce the system before suspend.

Stop is implemented by reusing the thread_single(9) with the special
mode SINGLE_ALLPROC.  SINGLE_ALLPROC differs from the existing
single-threading modes by allowing (requiring) caller to operate on
other process.  Interruptible sleeps for !TDF_SBDRY threads are
suspended like SIGSTOP does it, instead of aborting the sleep, like
SINGLE_NO_EXIT, to avoid spurious EINTRs on resume.

Provide debugging sysctl debug.stop_all_proc, which causes total stop
and suspends syncer, while waiting for variable reset for resume.  It
is used for debugging; should be removed after the real use of the
interface is added.

In collaboration with:	pho
Discussed with:	avg
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
This commit is contained in:
Konstantin Belousov 2014-12-13 16:18:29 +00:00
parent 0061ddb3ed
commit 6ddcc23386
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=275745
9 changed files with 244 additions and 55 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
bin/ps/ps.1
View File

@ -29,7 +29,7 @@
.\" @(#)ps.1 8.3 (Berkeley) 4/18/94
.\" $FreeBSD$
.\"
.Dd August 27, 2014
.Dd December 9, 2014
.Dt PS 1
.Os
.Sh NAME
@ -332,6 +332,7 @@ the include file
.It Dv "P_SINGLE_BOUNDARY" Ta No "0x400000" Ta "Threads should suspend at user boundary"
.It Dv "P_HWPMC" Ta No "0x800000" Ta "Process is using HWPMCs"
.It Dv "P_JAILED" Ta No "0x1000000" Ta "Process is in jail"
.It Dv "P_TOTAL_STOP" Ta No "0x2000000" Ta "Stopped for system suspend"
.It Dv "P_INEXEC" Ta No "0x4000000" Ta "Process is in execve()"
.It Dv "P_STATCHILD" Ta No "0x8000000" Ta "Child process stopped or exited"
.It Dv "P_INMEM" Ta No "0x10000000" Ta "Loaded into memory"

6
sys/kern/kern_exec.c
View File

@ -289,7 +289,7 @@ kern_execve(td, args, mac_p)
args->endp - args->begin_envv);
if (p->p_flag & P_HADTHREADS) {
PROC_LOCK(p);
if (thread_single(SINGLE_BOUNDARY)) {
if (thread_single(p, SINGLE_BOUNDARY)) {
PROC_UNLOCK(p);
exec_free_args(args);
return (ERESTART); /* Try again later. */
@ -308,9 +308,9 @@ kern_execve(td, args, mac_p)
* force other threads to suicide.
*/
if (error == 0)
thread_single(SINGLE_EXIT);
thread_single(p, SINGLE_EXIT);
else
thread_single_end();
thread_single_end(p, SINGLE_BOUNDARY);
PROC_UNLOCK(p);
}
if ((td->td_pflags & TDP_EXECVMSPC) != 0) {

2
sys/kern/kern_exit.c
View File

@ -207,7 +207,7 @@ exit1(struct thread *td, int rv)
* re-check all suspension request, the thread should
* either be suspended there or exit.
*/
if (!thread_single(SINGLE_EXIT))
if (!thread_single(p, SINGLE_EXIT))
/*
* All other activity in this process is now
* stopped. Threading support has been turned

5
sys/kern/kern_fork.c
View File

@ -317,7 +317,7 @@ fork_norfproc(struct thread *td, int flags)
if (((p1->p_flag & (P_HADTHREADS|P_SYSTEM)) == P_HADTHREADS) &&
(flags & (RFCFDG | RFFDG))) {
PROC_LOCK(p1);
if (thread_single(SINGLE_BOUNDARY)) {
if (thread_single(p1, SINGLE_BOUNDARY)) {
PROC_UNLOCK(p1);
return (ERESTART);
}
@ -348,7 +348,7 @@ fork_norfproc(struct thread *td, int flags)
if (((p1->p_flag & (P_HADTHREADS|P_SYSTEM)) == P_HADTHREADS) &&
(flags & (RFCFDG | RFFDG))) {
PROC_LOCK(p1);
thread_single_end();
thread_single_end(p1, SINGLE_BOUNDARY);
PROC_UNLOCK(p1);
}
return (error);
@ -384,6 +384,7 @@ do_fork(struct thread *td, int flags, struct proc *p2, struct thread *td2,
p2->p_pid = trypid;
AUDIT_ARG_PID(p2->p_pid);
LIST_INSERT_HEAD(&allproc, p2, p_list);
allproc_gen++;
LIST_INSERT_HEAD(PIDHASH(p2->p_pid), p2, p_hash);
tidhash_add(td2);
PROC_LOCK(p2);

138
sys/kern/kern_proc.c
View File

@ -2896,3 +2896,141 @@ static SYSCTL_NODE(_kern_proc, KERN_PROC_OSREL, osrel, CTLFLAG_RW |
static SYSCTL_NODE(_kern_proc, KERN_PROC_SIGTRAMP, sigtramp, CTLFLAG_RD |
CTLFLAG_MPSAFE, sysctl_kern_proc_sigtramp,
"Process signal trampoline location");
int allproc_gen;
void
stop_all_proc(void)
{
struct proc *cp, *p;
int r, gen;
bool restart, seen_stopped, seen_exiting, stopped_some;
cp = curproc;
/*
* stop_all_proc() assumes that all process which have
* usermode must be stopped, except current process, for
* obvious reasons. Since other threads in the process
* establishing global stop could unstop something, disable
* calls from multithreaded processes as precaution. The
* service must not be user-callable anyway.
*/
KASSERT((cp->p_flag & P_HADTHREADS) == 0 ||
(cp->p_flag & P_KTHREAD) != 0, ("mt stop_all_proc"));
allproc_loop:
sx_xlock(&allproc_lock);
gen = allproc_gen;
seen_exiting = seen_stopped = stopped_some = restart = false;
LIST_REMOVE(cp, p_list);
LIST_INSERT_HEAD(&allproc, cp, p_list);
for (;;) {
p = LIST_NEXT(cp, p_list);
if (p == NULL)
break;
LIST_REMOVE(cp, p_list);
LIST_INSERT_AFTER(p, cp, p_list);
PROC_LOCK(p);
if ((p->p_flag & (P_KTHREAD | P_SYSTEM |
P_TOTAL_STOP)) != 0) {
PROC_UNLOCK(p);
continue;
}
if ((p->p_flag & P_WEXIT) != 0) {
seen_exiting = true;
PROC_UNLOCK(p);
continue;
}
if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) {
/*
* Stopped processes are tolerated when there
* are no other processes which might continue
* them. P_STOPPED_SINGLE but not
* P_TOTAL_STOP process still has at least one
* thread running.
*/
seen_stopped = true;
PROC_UNLOCK(p);
continue;
}
_PHOLD(p);
sx_xunlock(&allproc_lock);
r = thread_single(p, SINGLE_ALLPROC);
if (r != 0)
restart = true;
else
stopped_some = true;
_PRELE(p);
PROC_UNLOCK(p);
sx_xlock(&allproc_lock);
}
/* Catch forked children we did not see in iteration. */
if (gen != allproc_gen)
restart = true;
sx_xunlock(&allproc_lock);
if (restart || stopped_some || seen_exiting || seen_stopped) {
kern_yield(PRI_USER);
goto allproc_loop;
}
}
void
resume_all_proc(void)
{
struct proc *cp, *p;
cp = curproc;
sx_xlock(&allproc_lock);
LIST_REMOVE(cp, p_list);
LIST_INSERT_HEAD(&allproc, cp, p_list);
for (;;) {
p = LIST_NEXT(cp, p_list);
if (p == NULL)
break;
LIST_REMOVE(cp, p_list);
LIST_INSERT_AFTER(p, cp, p_list);
PROC_LOCK(p);
if ((p->p_flag & P_TOTAL_STOP) != 0) {
sx_xunlock(&allproc_lock);
_PHOLD(p);
thread_single_end(p, SINGLE_ALLPROC);
_PRELE(p);
PROC_UNLOCK(p);
sx_xlock(&allproc_lock);
} else {
PROC_UNLOCK(p);
}
}
sx_xunlock(&allproc_lock);
}
#define TOTAL_STOP_DEBUG 1
#ifdef TOTAL_STOP_DEBUG
volatile static int ap_resume;
#include <sys/mount.h>
static int
sysctl_debug_stop_all_proc(SYSCTL_HANDLER_ARGS)
{
int error, val;
val = 0;
ap_resume = 0;
error = sysctl_handle_int(oidp, &val, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (val != 0) {
stop_all_proc();
syncer_suspend();
while (ap_resume == 0)
;
syncer_resume();
resume_all_proc();
}
return (0);
}
SYSCTL_PROC(_debug, OID_AUTO, stop_all_proc, CTLTYPE_INT | CTLFLAG_RW |
CTLFLAG_MPSAFE, (void *)&ap_resume, 0, sysctl_debug_stop_all_proc, "I",
"");
#endif

6
sys/kern/kern_sig.c
View File

@ -2491,7 +2491,7 @@ ptracestop(struct thread *td, int sig)
cv_broadcast(&p->p_dbgwait);
}
stopme:
thread_suspend_switch(td);
thread_suspend_switch(td, p);
if (p->p_xthread == td)
p->p_xthread = NULL;
if (!(p->p_flag & P_TRACED))
@ -2752,7 +2752,7 @@ issignal(struct thread *td)
p->p_xstat = sig;
PROC_SLOCK(p);
sig_suspend_threads(td, p, 0);
thread_suspend_switch(td);
thread_suspend_switch(td, p);
PROC_SUNLOCK(p);
mtx_lock(&ps->ps_mtx);
break;
@ -2933,7 +2933,7 @@ sigexit(td, sig)
* XXX If another thread attempts to single-thread before us
* (e.g. via fork()), we won't get a dump at all.
*/
if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) {
if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) {
p->p_sig = sig;
/*
* Log signals which would cause core dumps

119
sys/kern/kern_thread.c
View File

@ -445,7 +445,7 @@ thread_exit(void)
if (p->p_numthreads == p->p_suspcount) {
thread_lock(p->p_singlethread);
wakeup_swapper = thread_unsuspend_one(
p->p_singlethread);
p->p_singlethread, p);
thread_unlock(p->p_singlethread);
if (wakeup_swapper)
kick_proc0();
@ -576,7 +576,7 @@ calc_remaining(struct proc *p, int mode)
remaining = p->p_numthreads;
else if (mode == SINGLE_BOUNDARY)
remaining = p->p_numthreads - p->p_boundary_count;
else if (mode == SINGLE_NO_EXIT)
else if (mode == SINGLE_NO_EXIT || mode == SINGLE_ALLPROC)
remaining = p->p_numthreads - p->p_suspcount;
else
panic("calc_remaining: wrong mode %d", mode);
@ -587,7 +587,7 @@ static int
remain_for_mode(int mode)
{
return (1);
return (mode == SINGLE_ALLPROC ? 0 : 1);
}
static int
@ -603,21 +603,41 @@ weed_inhib(int mode, struct thread *td2, struct proc *p)
switch (mode) {
case SINGLE_EXIT:
if (TD_IS_SUSPENDED(td2))
wakeup_swapper |= thread_unsuspend_one(td2);
wakeup_swapper |= thread_unsuspend_one(td2, p);
if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR) != 0)
wakeup_swapper |= sleepq_abort(td2, EINTR);
break;
case SINGLE_BOUNDARY:
if (TD_IS_SUSPENDED(td2) && (td2->td_flags & TDF_BOUNDARY) == 0)
wakeup_swapper |= thread_unsuspend_one(td2);
wakeup_swapper |= thread_unsuspend_one(td2, p);
if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR) != 0)
wakeup_swapper |= sleepq_abort(td2, ERESTART);
break;
case SINGLE_NO_EXIT:
if (TD_IS_SUSPENDED(td2) && (td2->td_flags & TDF_BOUNDARY) == 0)
wakeup_swapper |= thread_unsuspend_one(td2);
wakeup_swapper |= thread_unsuspend_one(td2, p);
if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR) != 0)
wakeup_swapper |= sleepq_abort(td2, ERESTART);
case SINGLE_ALLPROC:
/*
* ALLPROC suspend tries to avoid spurious EINTR for
* threads sleeping interruptable, by suspending the
* thread directly, similarly to sig_suspend_threads().
* Since such sleep is not performed at the user
* boundary, TDF_BOUNDARY flag is not set, and TDF_ALLPROCSUSP
* is used to avoid immediate un-suspend.
*/
if (TD_IS_SUSPENDED(td2) && (td2->td_flags & (TDF_BOUNDARY |
TDF_ALLPROCSUSP)) == 0)
wakeup_swapper |= thread_unsuspend_one(td2, p);
if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR) != 0) {
if ((td2->td_flags & TDF_SBDRY) == 0) {
thread_suspend_one(td2);
td2->td_flags |= TDF_ALLPROCSUSP;
} else {
wakeup_swapper |= sleepq_abort(td2, ERESTART);
}
}
break;
}
return (wakeup_swapper);
@ -637,19 +657,29 @@ weed_inhib(int mode, struct thread *td2, struct proc *p)
* any sleeping threads that are interruptable. (PCATCH).
*/
int
thread_single(int mode)
thread_single(struct proc *p, int mode)
{
struct thread *td;
struct thread *td2;
struct proc *p;
int remaining, wakeup_swapper;
td = curthread;
p = td->td_proc;
KASSERT(mode == SINGLE_EXIT || mode == SINGLE_BOUNDARY ||
mode == SINGLE_ALLPROC || mode == SINGLE_NO_EXIT,
("invalid mode %d", mode));
/*
* If allowing non-ALLPROC singlethreading for non-curproc
* callers, calc_remaining() and remain_for_mode() should be
* adjusted to also account for td->td_proc != p. For now
* this is not implemented because it is not used.
*/
KASSERT((mode == SINGLE_ALLPROC && td->td_proc != p) ||
(mode != SINGLE_ALLPROC && td->td_proc == p),
("mode %d proc %p curproc %p", mode, p, td->td_proc));
mtx_assert(&Giant, MA_NOTOWNED);
PROC_LOCK_ASSERT(p, MA_OWNED);
if ((p->p_flag & P_HADTHREADS) == 0)
if ((p->p_flag & P_HADTHREADS) == 0 && mode != SINGLE_ALLPROC)
return (0);
/* Is someone already single threading? */
@ -666,6 +696,8 @@ thread_single(int mode)
else
p->p_flag &= ~P_SINGLE_BOUNDARY;
}
if (mode == SINGLE_ALLPROC)
p->p_flag |= P_TOTAL_STOP;
p->p_flag |= P_STOPPED_SINGLE;
PROC_SLOCK(p);
p->p_singlethread = td;
@ -679,13 +711,13 @@ thread_single(int mode)
continue;
thread_lock(td2);
td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK;
if (TD_IS_INHIBITED(td2))
if (TD_IS_INHIBITED(td2)) {
wakeup_swapper |= weed_inhib(mode, td2, p);
#ifdef SMP
else if (TD_IS_RUNNING(td2) && td != td2) {
} else if (TD_IS_RUNNING(td2) && td != td2) {
forward_signal(td2);
}
#endif
}
thread_unlock(td2);
}
if (wakeup_swapper)
@ -703,7 +735,7 @@ thread_single(int mode)
* Wake us up when everyone else has suspended.
* In the mean time we suspend as well.
*/
thread_suspend_switch(td);
thread_suspend_switch(td, p);
remaining = calc_remaining(p, mode);
}
if (mode == SINGLE_EXIT) {
@ -813,8 +845,9 @@ thread_suspend_check(int return_instead)
* Ignore suspend requests for stop signals if they
* are deferred.
*/
if (P_SHOULDSTOP(p) == P_STOPPED_SIG &&
td->td_flags & TDF_SBDRY) {
if ((P_SHOULDSTOP(p) == P_STOPPED_SIG ||
(p->p_flag & P_TOTAL_STOP) != 0) &&
(td->td_flags & TDF_SBDRY) != 0) {
KASSERT(return_instead,
("TDF_SBDRY set for unsafe thread_suspend_check"));
return (0);
@ -841,7 +874,7 @@ thread_suspend_check(int return_instead)
if (p->p_numthreads == p->p_suspcount + 1) {
thread_lock(p->p_singlethread);
wakeup_swapper =
thread_unsuspend_one(p->p_singlethread);
thread_unsuspend_one(p->p_singlethread, p);
thread_unlock(p->p_singlethread);
if (wakeup_swapper)
kick_proc0();
@ -874,11 +907,9 @@ thread_suspend_check(int return_instead)
}
void
thread_suspend_switch(struct thread *td)
thread_suspend_switch(struct thread *td, struct proc *p)
{
struct proc *p;
p = td->td_proc;
KASSERT(!TD_IS_SUSPENDED(td), ("already suspended"));
PROC_LOCK_ASSERT(p, MA_OWNED);
PROC_SLOCK_ASSERT(p, MA_OWNED);
@ -886,8 +917,10 @@ thread_suspend_switch(struct thread *td)
* We implement thread_suspend_one in stages here to avoid
* dropping the proc lock while the thread lock is owned.
*/
thread_stopped(p);
p->p_suspcount++;
if (p == td->td_proc) {
thread_stopped(p);
p->p_suspcount++;
}
PROC_UNLOCK(p);
thread_lock(td);
td->td_flags &= ~TDF_NEEDSUSPCHK;
@ -905,8 +938,9 @@ thread_suspend_switch(struct thread *td)
void
thread_suspend_one(struct thread *td)
{
struct proc *p = td->td_proc;
struct proc *p;
p = td->td_proc;
PROC_SLOCK_ASSERT(p, MA_OWNED);
THREAD_LOCK_ASSERT(td, MA_OWNED);
KASSERT(!TD_IS_SUSPENDED(td), ("already suspended"));
@ -917,15 +951,17 @@ thread_suspend_one(struct thread *td)
}
int
thread_unsuspend_one(struct thread *td)
thread_unsuspend_one(struct thread *td, struct proc *p)
{
struct proc *p = td->td_proc;
PROC_SLOCK_ASSERT(p, MA_OWNED);
THREAD_LOCK_ASSERT(td, MA_OWNED);
KASSERT(TD_IS_SUSPENDED(td), ("Thread not suspended"));
TD_CLR_SUSPENDED(td);
p->p_suspcount--;
td->td_flags &= ~TDF_ALLPROCSUSP;
if (td->td_proc == p) {
PROC_SLOCK_ASSERT(p, MA_OWNED);
p->p_suspcount--;
}
return (setrunnable(td));
}
@ -945,7 +981,7 @@ thread_unsuspend(struct proc *p)
FOREACH_THREAD_IN_PROC(p, td) {
thread_lock(td);
if (TD_IS_SUSPENDED(td)) {
wakeup_swapper |= thread_unsuspend_one(td);
wakeup_swapper |= thread_unsuspend_one(td, p);
}
thread_unlock(td);
}
@ -956,9 +992,12 @@ thread_unsuspend(struct proc *p)
* threading request. Now we've downgraded to single-threaded,
* let it continue.
*/
thread_lock(p->p_singlethread);
wakeup_swapper = thread_unsuspend_one(p->p_singlethread);
thread_unlock(p->p_singlethread);
if (p->p_singlethread->td_proc == p) {
thread_lock(p->p_singlethread);
wakeup_swapper = thread_unsuspend_one(
p->p_singlethread, p);
thread_unlock(p->p_singlethread);
}
}
if (wakeup_swapper)
kick_proc0();
@ -968,15 +1007,20 @@ thread_unsuspend(struct proc *p)
* End the single threading mode..
*/
void
thread_single_end(void)
thread_single_end(struct proc *p, int mode)
{
struct thread *td;
struct proc *p;
int wakeup_swapper;
p = curproc;
KASSERT(mode == SINGLE_EXIT || mode == SINGLE_BOUNDARY ||
mode == SINGLE_ALLPROC || mode == SINGLE_NO_EXIT,
("invalid mode %d", mode));
PROC_LOCK_ASSERT(p, MA_OWNED);
p->p_flag &= ~(P_STOPPED_SINGLE | P_SINGLE_EXIT | P_SINGLE_BOUNDARY);
KASSERT((mode == SINGLE_ALLPROC && (p->p_flag & P_TOTAL_STOP) != 0) ||
(mode != SINGLE_ALLPROC && (p->p_flag & P_TOTAL_STOP) == 0),
("mode %d does not match P_TOTAL_STOP", mode));
p->p_flag &= ~(P_STOPPED_SINGLE | P_SINGLE_EXIT | P_SINGLE_BOUNDARY |
P_TOTAL_STOP);
PROC_SLOCK(p);
p->p_singlethread = NULL;
wakeup_swapper = 0;
@ -986,12 +1030,11 @@ thread_single_end(void)
* on the process. The single threader must be allowed
* to continue however as this is a bad place to stop.
*/
if (p->p_numthreads != remain_for_mode(SINGLE_EXIT) &&
!P_SHOULDSTOP(p)) {
if (p->p_numthreads != remain_for_mode(mode) && !P_SHOULDSTOP(p)) {
FOREACH_THREAD_IN_PROC(p, td) {
thread_lock(td);
if (TD_IS_SUSPENDED(td)) {
wakeup_swapper |= thread_unsuspend_one(td);
wakeup_swapper |= thread_unsuspend_one(td, p);
}
thread_unlock(td);
}

3
sys/rpc/svc.c
View File

@ -1190,7 +1190,8 @@ svc_run_internal(SVCGROUP *grp, bool_t ismaster)
mtx_unlock(&grp->sg_lock);
p = curproc;
PROC_LOCK(p);
if (P_SHOULDSTOP(p)) {
if (P_SHOULDSTOP(p) ||
(p->p_flag & P_TOTAL_STOP) != 0) {
thread_suspend_check(0);
PROC_UNLOCK(p);
mtx_lock(&grp->sg_lock);

17
sys/sys/proc.h
View File

@ -361,7 +361,7 @@ do { \
#define TDF_CANSWAP 0x00000040 /* Thread can be swapped. */
#define TDF_SLEEPABORT 0x00000080 /* sleepq_abort was called. */
#define TDF_KTH_SUSP 0x00000100 /* kthread is suspended */
#define TDF_UNUSED09 0x00000200 /* --available-- */
#define TDF_ALLPROCSUSP 0x00000200 /* suspended by SINGLE_ALLPROC */
#define TDF_BOUNDARY 0x00000400 /* Thread suspended at user boundary */
#define TDF_ASTPENDING 0x00000800 /* Thread has some asynchronous events. */
#define TDF_TIMOFAIL 0x00001000 /* Timeout from sleep after we were awake. */
@ -652,7 +652,7 @@ struct proc {
#define P_SINGLE_BOUNDARY 0x400000 /* Threads should suspend at user boundary. */
#define P_HWPMC 0x800000 /* Process is using HWPMCs */
#define P_JAILED 0x1000000 /* Process is in jail. */
#define P_UNUSED1 0x2000000
#define P_TOTAL_STOP 0x2000000 /* Stopped in proc_stop_total. */
#define P_INEXEC 0x4000000 /* Process is in execve(). */
#define P_STATCHILD 0x8000000 /* Child process stopped or exited. */
#define P_INMEM 0x10000000 /* Loaded into memory. */
@ -713,6 +713,7 @@ struct proc {
#define SINGLE_NO_EXIT 0
#define SINGLE_EXIT 1
#define SINGLE_BOUNDARY 2
#define SINGLE_ALLPROC 3
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_PARGS);
@ -839,6 +840,7 @@ extern LIST_HEAD(pgrphashhead, pgrp) *pgrphashtbl;
extern u_long pgrphash;
extern struct sx allproc_lock;
extern int allproc_gen;
extern struct sx proctree_lock;
extern struct mtx ppeers_lock;
extern struct proc proc0; /* Process slot for swapper. */
@ -962,8 +964,8 @@ void thread_exit(void) __dead2;
void thread_free(struct thread *td);
void thread_link(struct thread *td, struct proc *p);
void thread_reap(void);
int thread_single(int how);
void thread_single_end(void);
int thread_single(struct proc *p, int how);
void thread_single_end(struct proc *p, int how);
void thread_stash(struct thread *td);
void thread_stopped(struct proc *p);
void childproc_stopped(struct proc *child, int reason);
@ -971,14 +973,17 @@ void childproc_continued(struct proc *child);
void childproc_exited(struct proc *child);
int thread_suspend_check(int how);
bool thread_suspend_check_needed(void);
void thread_suspend_switch(struct thread *);
void thread_suspend_switch(struct thread *, struct proc *p);
void thread_suspend_one(struct thread *td);
void thread_unlink(struct thread *td);
void thread_unsuspend(struct proc *p);
int thread_unsuspend_one(struct thread *td);
int thread_unsuspend_one(struct thread *td, struct proc *p);
void thread_wait(struct proc *p);
struct thread *thread_find(struct proc *p, lwpid_t tid);
void stop_all_proc(void);
void resume_all_proc(void);
static __inline int
curthread_pflags_set(int flags)
{