git: 5e5675cb4bfa - main - Remove struct proc p_singlethr member

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=5e5675cb4bfa80b6026b5c781d6fa2cc9254468f

commit 5e5675cb4bfa80b6026b5c781d6fa2cc9254468f
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2022-08-12 19:59:56 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2022-08-20 17:34:30 +0000

    Remove struct proc p_singlethr member
    
    It does not serve any purpose after we stopped doing
    thread_single(SINGLE_ALLPROC) from stoppable user processes.
    
    Reviewed by:    markj
    Tested by:      pho
    Sponsored by:   The FreeBSD Foundation
    MFC after:      2 weeks
    Differential revision:  https://reviews.freebsd.org/D36207
---
 sys/kern/kern_exec.c    | 9 ---------
 sys/kern/kern_exit.c    | 2 --
 sys/kern/kern_fork.c    | 8 --------
 sys/kern/kern_procctl.c | 6 ------
 sys/kern/kern_thread.c  | 6 +++---
 sys/sys/proc.h          | 2 --
 6 files changed, 3 insertions(+), 30 deletions(-)

diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index 0ead8d81fe59..364c10987ea6 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -307,17 +307,8 @@ pre_execve(struct thread *td, struct vmspace **oldvmspace)
 	p = td->td_proc;
 	if ((p->p_flag & P_HADTHREADS) != 0) {
 		PROC_LOCK(p);
-		while (p->p_singlethr > 0) {
-			error = msleep(&p->p_singlethr, &p->p_mtx,
-			    PWAIT | PCATCH, "exec1t", 0);
-			if (error != 0) {
-				error = ERESTART;
-				goto unlock;
-			}
-		}
 		if (thread_single(p, SINGLE_BOUNDARY) != 0)
 			error = ERESTART;
-unlock:
 		PROC_UNLOCK(p);
 	}
 	KASSERT(error != 0 || (td->td_pflags & TDP_EXECVMSPC) == 0,
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
index 4c3821ddfa72..cb51193a26e0 100644
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -218,8 +218,6 @@ proc_set_p2_wexit(struct proc *p)
 {
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	p->p_flag2 |= P2_WEXIT;
-	while (p->p_singlethr > 0)
-		msleep(&p->p_singlethr, &p->p_mtx, PWAIT | PCATCH, "exit1t", 0);
 }
 
 /*
diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index c71a0422b1e2..b4f96686caba 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -319,17 +319,9 @@ fork_norfproc(struct thread *td, int flags)
 	 * must ensure that other threads do not concurrently create a second
 	 * process sharing the vmspace, see vmspace_unshare().
 	 */
-again:
 	if ((p1->p_flag & (P_HADTHREADS | P_SYSTEM)) == P_HADTHREADS &&
 	    ((flags & (RFCFDG | RFFDG)) != 0 || (flags & RFMEM) == 0)) {
 		PROC_LOCK(p1);
-		if (p1->p_singlethr > 0) {
-			error = msleep(&p1->p_singlethr, &p1->p_mtx,
-			    PWAIT | PCATCH | PDROP, "rfork1t", 0);
-			if (error != 0)
-				return (ERESTART);
-			goto again;
-		}
 		if (thread_single(p1, SINGLE_BOUNDARY)) {
 			PROC_UNLOCK(p1);
 			return (ERESTART);
diff --git a/sys/kern/kern_procctl.c b/sys/kern/kern_procctl.c
index 1fb1183741d6..9d48b04dde48 100644
--- a/sys/kern/kern_procctl.c
+++ b/sys/kern/kern_procctl.c
@@ -477,15 +477,9 @@ reap_kill_subtree(struct thread *td, struct proc *p, struct proc *reaper,
 		PROC_UNLOCK(td->td_proc);
 		goto out;
 	}
-	td->td_proc->p_singlethr++;
 	PROC_UNLOCK(td->td_proc);
 	while (reap_kill_subtree_once(td, p, reaper, &pids, w))
 	       ;
-	PROC_LOCK(td->td_proc);
-	td->td_proc->p_singlethr--;
-	if (td->td_proc->p_singlethr == 0)
-		wakeup(&p->p_singlethr);
-	PROC_UNLOCK(td->td_proc);
 out:
 	clean_unrhdr(&pids);
 	clear_unrhdr(&pids);
diff --git a/sys/kern/kern_thread.c b/sys/kern/kern_thread.c
index a15488b29cb6..bfd153844464 100644
--- a/sys/kern/kern_thread.c
+++ b/sys/kern/kern_thread.c
@@ -99,7 +99,7 @@ _Static_assert(offsetof(struct proc, p_pid) == 0xc4,
     "struct proc KBI p_pid");
 _Static_assert(offsetof(struct proc, p_filemon) == 0x3c8,
     "struct proc KBI p_filemon");
-_Static_assert(offsetof(struct proc, p_comm) == 0x3e4,
+_Static_assert(offsetof(struct proc, p_comm) == 0x3e0,
     "struct proc KBI p_comm");
 _Static_assert(offsetof(struct proc, p_emuldata) == 0x4c8,
     "struct proc KBI p_emuldata");
@@ -119,9 +119,9 @@ _Static_assert(offsetof(struct proc, p_pid) == 0x78,
     "struct proc KBI p_pid");
 _Static_assert(offsetof(struct proc, p_filemon) == 0x270,
     "struct proc KBI p_filemon");
-_Static_assert(offsetof(struct proc, p_comm) == 0x288,
+_Static_assert(offsetof(struct proc, p_comm) == 0x284,
     "struct proc KBI p_comm");
-_Static_assert(offsetof(struct proc, p_emuldata) == 0x314,
+_Static_assert(offsetof(struct proc, p_emuldata) == 0x310,
     "struct proc KBI p_emuldata");
 #endif
 
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 9d55f0b71e4f..8c2aa6391d69 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -720,8 +720,6 @@ struct proc {
 	int		p_pendingexits; /* (c) Count of pending thread exits. */
 	struct filemon	*p_filemon;	/* (c) filemon-specific data. */
 	int		p_pdeathsig;	/* (c) Signal from parent on exit. */
-	int		p_singlethr;	/* (c) Count of threads doing
-					   external thread_single() */
 /* End area that is zeroed on creation. */
 #define	p_endzero	p_magic