diff --git a/sys/amd64/linux/linux_sysvec.c b/sys/amd64/linux/linux_sysvec.c
--- a/sys/amd64/linux/linux_sysvec.c
+++ b/sys/amd64/linux/linux_sysvec.c
@@ -752,7 +752,8 @@
 	.sv_setregs	= linux_exec_setregs,
 	.sv_fixlimit	= NULL,
 	.sv_maxssiz	= NULL,
-	.sv_flags	= SV_ABI_LINUX | SV_LP64 | SV_SHP,
+	.sv_flags	= SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_IGNIGN |
+	    SV_SIG_WAITNDQ,
 	.sv_set_syscall_retval = linux_set_syscall_retval,
 	.sv_fetch_syscall_args = linux_fetch_syscall_args,
 	.sv_syscallnames = NULL,
diff --git a/sys/amd64/linux32/linux32_sysvec.c b/sys/amd64/linux32/linux32_sysvec.c
--- a/sys/amd64/linux32/linux32_sysvec.c
+++ b/sys/amd64/linux32/linux32_sysvec.c
@@ -919,7 +919,8 @@
 	.sv_setregs	= linux_exec_setregs,
 	.sv_fixlimit	= linux32_fixlimit,
 	.sv_maxssiz	= &linux32_maxssiz,
-	.sv_flags	= SV_ABI_LINUX | SV_ILP32 | SV_IA32 | SV_SHP,
+	.sv_flags	= SV_ABI_LINUX | SV_ILP32 | SV_IA32 | SV_SHP |
+	    SV_SIG_IGNIGN | SV_SIG_WAITNDQ,
 	.sv_set_syscall_retval = linux32_set_syscall_retval,
 	.sv_fetch_syscall_args = linux32_fetch_syscall_args,
 	.sv_syscallnames = NULL,
diff --git a/sys/arm64/linux/linux_sysvec.c b/sys/arm64/linux/linux_sysvec.c
--- a/sys/arm64/linux/linux_sysvec.c
+++ b/sys/arm64/linux/linux_sysvec.c
@@ -429,7 +429,8 @@
 	.sv_setregs	= linux_exec_setregs,
 	.sv_fixlimit	= NULL,
 	.sv_maxssiz	= NULL,
-	.sv_flags	= SV_ABI_LINUX | SV_LP64 | SV_SHP,
+	.sv_flags	= SV_ABI_LINUX | SV_LP64 | SV_SHP | SV_SIG_IGNIGN |
+	    SV_SIG_WAITNDQ,
 	.sv_set_syscall_retval = linux_set_syscall_retval,
 	.sv_fetch_syscall_args = linux_fetch_syscall_args,
 	.sv_syscallnames = NULL,
diff --git a/sys/i386/linux/linux_sysvec.c b/sys/i386/linux/linux_sysvec.c
--- a/sys/i386/linux/linux_sysvec.c
+++ b/sys/i386/linux/linux_sysvec.c
@@ -859,7 +859,8 @@
 	.sv_setregs	= linux_exec_setregs,
 	.sv_fixlimit	= NULL,
 	.sv_maxssiz	= NULL,
-	.sv_flags	= SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32,
+	.sv_flags	= SV_ABI_LINUX | SV_AOUT | SV_IA32 | SV_ILP32 |
+	    SV_SIG_IGNIGN | SV_SIG_WAITNDQ,
 	.sv_set_syscall_retval = linux_set_syscall_retval,
 	.sv_fetch_syscall_args = linux_fetch_syscall_args,
 	.sv_syscallnames = NULL,
@@ -897,7 +898,8 @@
 	.sv_setregs	= linux_exec_setregs,
 	.sv_fixlimit	= NULL,
 	.sv_maxssiz	= NULL,
-	.sv_flags	= SV_ABI_LINUX | SV_IA32 | SV_ILP32 | SV_SHP,
+	.sv_flags	= SV_ABI_LINUX | SV_IA32 | SV_ILP32 | SV_SHP |
+	    SV_SIG_IGNIGN | SV_SIG_WAITNDQ,
 	.sv_set_syscall_retval = linux_set_syscall_retval,
 	.sv_fetch_syscall_args = linux_fetch_syscall_args,
 	.sv_syscallnames = NULL,
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c
--- a/sys/kern/kern_exit.c
+++ b/sys/kern/kern_exit.c
@@ -105,6 +105,11 @@
     &kern_kill_on_dbg_exit, 0,
     "Kill ptraced processes when debugger exits");
 
+static int kern_wait_dequeue_sigchld = 1;
+SYSCTL_INT(_kern, OID_AUTO, wait_dequeue_sigchld, CTLFLAG_RWTUN,
+    &kern_wait_dequeue_sigchld, 0,
+    "Dequeue SIGCHLD on wait(2) for live process");
+
 struct proc *
 proc_realparent(struct proc *child)
 {
@@ -1207,9 +1212,12 @@
 			p->p_flag &= ~P_CONTINUED;
 		else
 			p->p_flag |= P_WAITED;
-		PROC_LOCK(td->td_proc);
-		sigqueue_take(p->p_ksi);
-		PROC_UNLOCK(td->td_proc);
+		if (kern_wait_dequeue_sigchld &&
+		    (td->td_proc->p_sysent->sv_flags & SV_SIG_WAITNDQ) == 0) {
+			PROC_LOCK(td->td_proc);
+			sigqueue_take(p->p_ksi);
+			PROC_UNLOCK(td->td_proc);
+		}
 	}
 	sx_xunlock(&proctree_lock);
 	if (siginfo != NULL) {
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -163,6 +163,12 @@
     "Fetch sigfastblock word on each syscall entry for proper "
     "blocking semantic");
 
+static bool	kern_sig_ign_ign = true;
+SYSCTL_BOOL(_kern, OID_AUTO, sig_ign_ign, CTLFLAG_RWTUN,
+    &kern_sig_ign_ign, 0,
+    "Ignore ignored signals on delivery, otherwise queue them to "
+    "the target queue");
+
 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL);
 
 /*
@@ -1285,6 +1291,9 @@
 	PROC_LOCK(p);
 	saved_mask = td->td_sigmask;
 	SIGSETNAND(td->td_sigmask, waitset);
+	if ((p->p_sysent->sv_flags & SV_SIG_IGNIGN) != 0 ||
+	    !kern_sig_ign_ign)
+		td->td_pflags2 |= TDP2_SIGWAIT;
 	for (;;) {
 		mtx_lock(&ps->ps_mtx);
 		sig = cursig(td);
@@ -1329,15 +1338,13 @@
 
 		error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo);
 
-		if (timeout != NULL) {
-			if (error == ERESTART) {
-				/* Timeout can not be restarted. */
-				error = EINTR;
-			} else if (error == EAGAIN) {
-				/* We will calculate timeout by ourself. */
-				error = 0;
-			}
-		}
+		/* The syscalls can not be restarted. */
+		if (error == ERESTART)
+			error = EINTR;
+
+		/* We will calculate timeout by ourself. */
+		if (timeout != NULL && error == EAGAIN)
+			error = 0;
 
 		/*
 		 * If PTRACE_SCE or PTRACE_SCX were set after
@@ -1349,6 +1356,7 @@
 		if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0)
 			traced = true;
 	}
+	td->td_pflags2 &= ~TDP2_SIGWAIT;
 
 	new_block = saved_mask;
 	SIGSETNAND(new_block, td->td_sigmask);
@@ -2197,22 +2205,25 @@
 	SDT_PROBE3(proc, , , signal__send, td, p, sig);
 
 	/*
-	 * If the signal is being ignored,
-	 * then we forget about it immediately.
-	 * (Note: we don't set SIGCONT in ps_sigignore,
-	 * and if it is set to SIG_IGN,
-	 * action will be SIG_DFL here.)
+	 * If the signal is being ignored, then we forget about it
+	 * immediately, except when the target process executes
+	 * sigwait().  (Note: we don't set SIGCONT in ps_sigignore,
+	 * and if it is set to SIG_IGN, action will be SIG_DFL here.)
 	 */
 	mtx_lock(&ps->ps_mtx);
 	if (SIGISMEMBER(ps->ps_sigignore, sig)) {
-		SDT_PROBE3(proc, , , signal__discard, td, p, sig);
+		if (kern_sig_ign_ign &&
+		    (p->p_sysent->sv_flags & SV_SIG_IGNIGN) == 0) {
+			SDT_PROBE3(proc, , , signal__discard, td, p, sig);
 
-		mtx_unlock(&ps->ps_mtx);
-		if (ksi && (ksi->ksi_flags & KSI_INS))
-			ksiginfo_tryfree(ksi);
-		return (ret);
-	}
-	if (SIGISMEMBER(td->td_sigmask, sig))
+			mtx_unlock(&ps->ps_mtx);
+			if (ksi && (ksi->ksi_flags & KSI_INS))
+				ksiginfo_tryfree(ksi);
+			return (ret);
+		} else {
+			action = SIG_CATCH;
+		}
+	} else if (SIGISMEMBER(td->td_sigmask, sig))
 		action = SIG_HOLD;
 	else if (SIGISMEMBER(ps->ps_sigcatch, sig))
 		action = SIG_CATCH;
@@ -2947,11 +2958,13 @@
 		}
 
 		/*
-		 * We should see pending but ignored signals
-		 * only if P_TRACED was on when they were posted.
+		 * We should allow pending but ignored signals below
+		 * only if there is sigwait() active, or P_TRACED was
+		 * on when they were posted.
 		 */
 		if (SIGISMEMBER(ps->ps_sigignore, sig) &&
-		    (p->p_flag & P_TRACED) == 0) {
+		    (p->p_flag & P_TRACED) == 0 &&
+		    (td->td_pflags2 & TDP2_SIGWAIT) == 0) {
 			sigqueue_delete(&td->td_sigqueue, sig);
 			sigqueue_delete(&p->p_sigqueue, sig);
 			continue;
@@ -3063,10 +3076,11 @@
 				PROC_SUNLOCK(p);
 				mtx_lock(&ps->ps_mtx);
 				goto next;
-			} else if (prop & SIGPROP_IGNORE) {
+			} else if ((prop & SIGPROP_IGNORE) != 0 &&
+			    (td->td_pflags2 & TDP2_SIGWAIT) == 0) {
 				/*
-				 * Except for SIGCONT, shouldn't get here.
-				 * Default action is to ignore; drop it.
+				 * Default action is to ignore; drop it if
+				 * not in sigtimedwait().
 				 */
 				break;		/* == ignore */
 			} else
@@ -3074,15 +3088,10 @@
 			/*NOTREACHED*/
 
 		case (intptr_t)SIG_IGN:
-			/*
-			 * Masking above should prevent us ever trying
-			 * to take action on an ignored signal other
-			 * than SIGCONT, unless process is traced.
-			 */
-			if ((prop & SIGPROP_CONT) == 0 &&
-			    (p->p_flag & P_TRACED) == 0)
-				printf("issignal\n");
-			break;		/* == ignore */
+			if ((td->td_pflags2 & TDP2_SIGWAIT) == 0)
+				break;		/* == ignore */
+			else
+				return (sig);
 
 		default:
 			/*
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -529,6 +529,7 @@
 #define	TDP2_SBPAGES	0x00000001 /* Owns sbusy on some pages */
 #define	TDP2_COMPAT32RB	0x00000002 /* compat32 ABI for robust lists */
 #define	TDP2_ACCT	0x00000004 /* Doing accounting */
+#define	TDP2_SIGWAIT	0x00000008 /* Ignore ignored signals */
 
 /*
  * Reasons that the current thread can not be run yet.
diff --git a/sys/sys/sysent.h b/sys/sys/sysent.h
--- a/sys/sys/sysent.h
+++ b/sys/sys/sysent.h
@@ -161,6 +161,8 @@
 #define	SV_TIMEKEEP	0x040000	/* Shared page timehands. */
 #define	SV_ASLR		0x080000	/* ASLR allowed. */
 #define	SV_RNG_SEED_VER	0x100000	/* random(4) reseed generation. */
+#define	SV_SIG_IGNIGN	0x200000	/* Do not ignore ignored signals */
+#define	SV_SIG_WAITNDQ	0x400000	/* Wait does not dequeue SIGCHLD */
 
 #define	SV_ABI_MASK	0xff
 #define	SV_PROC_FLAG(p, x)	((p)->p_sysent->sv_flags & (x))