Remove uidinfo hash table lookup and maintenance out of chgproccnt() and

chgsbsize(), which are called rather frequently and may be called from an
interrupt context in the case of chgsbsize().  Instead, do the hash table
lookup and maintenance when credentials are changed, which is a lot less
frequent.  Add pointers to the uidinfo structures to the ucred and pcred
structures for fast access.  Pass a pointer to the credential to chgproccnt()
and chgsbsize() instead of passing the uid.  Add a reference count to the
uidinfo structure and use it to decide when to free the structure rather
than freeing the structure when the resource consumption drops to zero.
Move the resource tracking code from kern_proc.c to kern_resource.c.  Move
some duplicate code sequences in kern_prot.c to separate helper functions.
Change KASSERTs in this code to unconditional tests and calls to panic().

1 files changed, 1 insertions, 136 deletions

diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index 6a94bf7..7ec2628 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -61,25 +61,8 @@ SYSCTL_INT(_kern, OID_AUTO, ps_showallprocs, CTLFLAG_RW,
 
 static void pgdelete	__P((struct pgrp *));
 
-/*
- * Structure associated with user cacheing.
- */
-struct uidinfo {
-	LIST_ENTRY(uidinfo) ui_hash;
-	uid_t	ui_uid;
-	long	ui_proccnt;
-	rlim_t	ui_sbsize;
-};
-#define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
-static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
-static u_long uihash;		/* size of hash table - 1 */
-
 static void	orphanpg __P((struct pgrp *pg));
 
-static struct uidinfo	*uifind(uid_t uid);
-static struct uidinfo	*uicreate(uid_t uid);
-static int 	uifree(struct uidinfo *uip);
-
 /*
  * Other process lists
  */
@@ -102,126 +85,8 @@ procinit()
 	LIST_INIT(&zombproc);
 	pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
 	pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash);
-	uihashtbl = hashinit(maxproc / 16, M_PROC, &uihash);
 	proc_zone = zinit("PROC", sizeof (struct proc), 0, 0, 5);
-}
-
-/*
- * find/create a uidinfo struct for the uid passed in
- */
-static struct uidinfo *
-uifind(uid)
-	uid_t uid;
-{
-	struct uihashhead *uipp;
-	struct uidinfo *uip;
-
-	uipp = UIHASH(uid);
-	LIST_FOREACH(uip, uipp, ui_hash)
-		if (uip->ui_uid == uid)
-			break;
-
-	return (uip);
-}
-
-static struct uidinfo *
-uicreate(uid)
-	uid_t uid;
-{
-	struct uidinfo *uip, *norace;
-
-	MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_NOWAIT);
-	if (uip == NULL) {
-		MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK);
-		/*
-		 * if we M_WAITOK we must look afterwards or risk
-		 * redundant entries
-		 */
-		norace = uifind(uid);
-		if (norace != NULL) {
-			FREE(uip, M_PROC);
-			return (norace);
-		}
-	}
-	LIST_INSERT_HEAD(UIHASH(uid), uip, ui_hash);
-	uip->ui_uid = uid;
-	uip->ui_proccnt = 0;
-	uip->ui_sbsize = 0;
-	return (uip);
-}
-
-static int
-uifree(uip)
-	struct uidinfo *uip;
-{
-
-	if (uip->ui_sbsize == 0 && uip->ui_proccnt == 0) {
-		LIST_REMOVE(uip, ui_hash);
-		FREE(uip, M_PROC);
-		return (1);
-	}
-	return (0);
-}
-
-/*
- * Change the count associated with number of processes
- * a given user is using.  When 'max' is 0, don't enforce a limit
- */
-int
-chgproccnt(uid, diff, max)
-	uid_t	uid;
-	int	diff;
-	int	max;
-{
-	struct uidinfo *uip;
-
-	uip = uifind(uid);
-	if (diff < 0)
-		KASSERT(uip != NULL, ("reducing proccnt: lost count, uid = %d", uid));
-	if (uip == NULL)
-		uip = uicreate(uid);
-	/* don't allow them to exceed max, but allow subtraction */
-	if (diff > 0 && uip->ui_proccnt + diff > max && max != 0) {
-		(void)uifree(uip);
-		return (0);
-	}
-	uip->ui_proccnt += diff;
-	(void)uifree(uip);
-	return (1);
-}
-
-/*
- * Change the total socket buffer size a user has used.
- */
-int
-chgsbsize(uid, hiwat, to, max)
-	uid_t	uid;
-	u_long *hiwat;
-	u_long	to;
-	rlim_t	max;
-{
-	struct uidinfo *uip;
-	rlim_t diff;
-	int s;
-
-	uip = uifind(uid);
-	KASSERT(to >= *hiwat || uip != NULL,
-	    ("reducing sbsize: lost count, uid = %d", uid));
-	if (uip == NULL)
-		uip = uicreate(uid);
-	s = splnet();
-	diff = (rlim_t)to - (rlim_t)*hiwat;
-	/* don't allow them to exceed max, but allow subtraction */
-	if (diff > 0 && uip->ui_sbsize + diff > max) {
-		(void)uifree(uip);
-		splx(s);
-		return (0);
-	}
-	uip->ui_sbsize += diff;
-	*hiwat = to;
-	(void)uifree(uip);
-	splx(s);
-	return (1);
+	uihashinit();
 }
 
 /*