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, 3 insertions, 2 deletions

diff --git a/sys/kern/uipc_socket2.c b/sys/kern/uipc_socket2.c
index 8016436..4ed67e5 100644
--- a/sys/kern/uipc_socket2.c
+++ b/sys/kern/uipc_socket2.c
@@ -427,7 +427,7 @@ sbreserve(sb, cc, so, p)
 	 */
 	if ((u_quad_t)cc > (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES))
 		return (0);
-	if (!chgsbsize(so->so_cred->cr_uid, &sb->sb_hiwat, cc,
+	if (!chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, cc,
 	    p ? p->p_rlimit[RLIMIT_SBSIZE].rlim_cur : RLIM_INFINITY)) {
 		return (0);
 	}
@@ -447,7 +447,8 @@ sbrelease(sb, so)
 {
 
 	sbflush(sb);
-	(void)chgsbsize(so->so_cred->cr_uid, &sb->sb_hiwat, 0, RLIM_INFINITY);
+	(void)chgsbsize(so->so_cred->cr_uidinfo, &sb->sb_hiwat, 0,
+	    RLIM_INFINITY);
 	sb->sb_mbmax = 0;
 }