Lock struct pgrp, session and sigio.

New locks are:

- pgrpsess_lock which locks the whole pgrps and sessions,
- pg_mtx which protects the pgrp members, and
- s_mtx which protects the session members.

Please refer to sys/proc.h for the coverage of these locks.

Changes on the pgrp/session interface:

- pgfind() needs the pgrpsess_lock held.

- The caller of enterpgrp() is responsible to allocate a new pgrp and
  session.

- Call enterthispgrp() in order to enter an existing pgrp.

- pgsignal() requires a pgrp lock held.

Reviewed by:	jhb, alfred
Tested on:	cvsup.jp.FreeBSD.org
		(which is a quad-CPU machine running -current)

1 files changed, 4 insertions, 0 deletions

diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c
index 4bb6a70..39e3243 100644
--- a/sys/kern/subr_witness.c
+++ b/sys/kern/subr_witness.c
@@ -188,9 +188,12 @@ static struct lock_list_entry w_locklistdata[LOCK_CHILDCOUNT];
 
 static struct witness_order_list_entry order_lists[] = {
 	{ "Giant", &lock_class_mtx_sleep },
+	{ "pgrpsess", &lock_class_sx },
 	{ "proctree", &lock_class_sx },
 	{ "allproc", &lock_class_sx },
+	{ "process group", &lock_class_mtx_sleep },
 	{ "process lock", &lock_class_mtx_sleep },
+	{ "session", &lock_class_mtx_sleep },
 	{ "uidinfo hash", &lock_class_mtx_sleep },
 	{ "uidinfo struct", &lock_class_mtx_sleep },
 	{ NULL, NULL },
@@ -227,6 +230,7 @@ static struct witness_order_list_entry order_lists[] = {
 
 static const char *dup_list[] = {
 	"process lock",
+	"process group",
 	NULL
 };