Skip site navigation (1)Skip section navigation (2) 
Date:      Tue, 17 Apr 2012 14:31:02 +0000 (UTC)
From:      Edward Tomasz Napierala <trasz@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r234383 - head/sys/kern
Message-ID:  <201204171431.q3HEV2mx086128@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help 
Author: trasz
Date: Tue Apr 17 14:31:02 2012
New Revision: 234383
URL: http://svn.freebsd.org/changeset/base/234383

Log:
  Stop treating system processes as special.  This fixes panics
  like the one triggered by this:
  
  # kldload geom_vinum
  # pwait `pgrep -S gv_worker` &
  # kldunload geom_vinum
  
  or this:
  
  GEOM_JOURNAL: Shutting down geom gjournal 3464572051.
  panic: destroying non-empty racct: 1 allocated for resource 6
  
  which were tracked by jh@ to be caused by checking p->p_flag,
  while it wasn't initialised yet.  Basically, during fork, the code
  checked p_flag, concluded the process isn't marked as P_SYSTEM,
  incremented the counter, and later on, when exiting, checked that
  the process was marked as P_SYSTEM, and thus didn't decrement it.
  
  Also, I believe there wasn't any good reason for checking P_SYSTEM
  in the first place.
  
  Tested by:	jh

Modified:
  head/sys/kern/kern_racct.c
  head/sys/kern/kern_rctl.c

Modified: head/sys/kern/kern_racct.c
==============================================================================
--- head/sys/kern/kern_racct.c	Tue Apr 17 14:26:55 2012	(r234382)
+++ head/sys/kern/kern_racct.c	Tue Apr 17 14:31:02 2012	(r234383)
@@ -267,9 +267,6 @@ racct_add_locked(struct proc *p, int res
 	int error;
 #endif
 
-	if (p->p_flag & P_SYSTEM)
-		return (0);
-
 	SDT_PROBE(racct, kernel, rusage, add, p, resource, amount, 0, 0);
 
 	/*
@@ -344,9 +341,6 @@ void
 racct_add_force(struct proc *p, int resource, uint64_t amount)
 {
 
-	if (p->p_flag & P_SYSTEM)
-		return;
-
 	SDT_PROBE(racct, kernel, rusage, add_force, p, resource, amount, 0, 0);
 
 	/*
@@ -368,9 +362,6 @@ racct_set_locked(struct proc *p, int res
 	int error;
 #endif
 
-	if (p->p_flag & P_SYSTEM)
-		return (0);
-
 	SDT_PROBE(racct, kernel, rusage, set, p, resource, amount, 0, 0);
 
 	/*
@@ -426,9 +417,6 @@ racct_set_force(struct proc *p, int reso
 {
 	int64_t diff;
 
-	if (p->p_flag & P_SYSTEM)
-		return;
-
 	SDT_PROBE(racct, kernel, rusage, set, p, resource, amount, 0, 0);
 
 	/*
@@ -487,9 +475,6 @@ void
 racct_sub(struct proc *p, int resource, uint64_t amount)
 {
 
-	if (p->p_flag & P_SYSTEM)
-		return;
-
 	SDT_PROBE(racct, kernel, rusage, sub, p, resource, amount, 0, 0);
 
 	/*
@@ -556,12 +541,6 @@ racct_proc_fork(struct proc *parent, str
 	 */
 	racct_create(&child->p_racct);
 
-	/*
-	 * No resource accounting for kernel processes.
-	 */
-	if (child->p_flag & P_SYSTEM)
-		return (0);
-
 	PROC_LOCK(parent);
 	PROC_LOCK(child);
 	mtx_lock(&racct_lock);
@@ -723,8 +702,6 @@ racctd(void)
 		FOREACH_PROC_IN_SYSTEM(p) {
 			if (p->p_state != PRS_NORMAL)
 				continue;
-			if (p->p_flag & P_SYSTEM)
-				continue;
 
 			microuptime(&wallclock);
 			timevalsub(&wallclock, &p->p_stats->p_start);

Modified: head/sys/kern/kern_rctl.c
==============================================================================
--- head/sys/kern/kern_rctl.c	Tue Apr 17 14:26:55 2012	(r234382)
+++ head/sys/kern/kern_rctl.c	Tue Apr 17 14:31:02 2012	(r234383)
@@ -994,11 +994,6 @@ rctl_rule_add(struct rctl_rule *rule)
 	case RCTL_SUBJECT_TYPE_PROCESS:
 		p = rule->rr_subject.rs_proc;
 		KASSERT(p != NULL, ("rctl_rule_add: NULL proc"));
-		/*
-		 * No resource limits for system processes.
-		 */
-		if (p->p_flag & P_SYSTEM)
-			return (EPERM);
 
 		rctl_racct_add_rule(p->p_racct, rule);
 		/*
@@ -1036,8 +1031,6 @@ rctl_rule_add(struct rctl_rule *rule)
 	 */
 	sx_assert(&allproc_lock, SA_LOCKED);
 	FOREACH_PROC_IN_SYSTEM(p) {
-		if (p->p_flag & P_SYSTEM)
-			continue;
 		cred = p->p_ucred;
 		switch (rule->rr_subject_type) {
 		case RCTL_SUBJECT_TYPE_USER:
@@ -1284,10 +1277,6 @@ sys_rctl_get_racct(struct thread *td, st
 			error = EINVAL;
 			goto out;
 		}
-		if (p->p_flag & P_SYSTEM) {
-			error = EINVAL;
-			goto out;
-		}
 		outputsbuf = rctl_racct_to_sbuf(p->p_racct, 0);
 		break;
 	case RCTL_SUBJECT_TYPE_USER:
@@ -1719,20 +1708,7 @@ rctl_proc_fork(struct proc *parent, stru
 
 	LIST_INIT(&child->p_racct->r_rule_links);
 
-	/*
-	 * No limits for kernel processes.
-	 */
-	if (child->p_flag & P_SYSTEM)
-		return (0);
-
-	/*
-	 * Nothing to inherit from P_SYSTEM parents.
-	 */
-	if (parent->p_racct == NULL) {
-		KASSERT(parent->p_flag & P_SYSTEM,
-		    ("non-system process without racct; p = %p", parent));
-		return (0);
-	}
+	KASSERT(parent->p_racct != NULL, ("process without racct; p = %p", parent));
 
 	rw_wlock(&rctl_lock);

Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201204171431.q3HEV2mx086128>