git: 661d1135e4ed - main - pdfork.2: document kern.pdfork_implicit_nowaitpid

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=661d1135e4ed12d6017220ea654ae67a6956dc73

commit 661d1135e4ed12d6017220ea654ae67a6956dc73
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2026-09-03 17:56:51 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2026-09-07 16:04:00 +0000

    pdfork.2: document kern.pdfork_implicit_nowaitpid
    
    Reviewed by:    markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D59349
---
 lib/libsys/pdfork.2 | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/lib/libsys/pdfork.2 b/lib/libsys/pdfork.2
index 1806158e668f..ce8919fb6119 100644
--- a/lib/libsys/pdfork.2
+++ b/lib/libsys/pdfork.2
@@ -114,6 +114,17 @@ Set close-on-exec on process descriptor.
 .It Dv PD_NOWAITPID
 The parent cannot obtain the child's status with
 .Xr waitpid 2 .
+.Pp
+A consequence of not setting the flag is that the child' zombie is
+not reaped until the
+.Xr waitpid 2
+call is performed on the child' PID.
+Setting the
+.Dv
+kern.pdfork_implicit_nowaitpid
+sysctl MIB to
+.Dv true
+makes the system behave as if the flag is always passed.
 .It Dv PD_PTRACE_CAP
 Enable
 .Xr pdptrace 2