* Add a "how" argument to uma_zone constructors and initialization functions

  so that they know whether the allocation is supposed to be able to sleep
  or not.
* Allow uma_zone constructors and initialation functions to return either
  success or error.  Almost all of the ones in the tree currently return
  success unconditionally, but mbuf is a notable exception: the packet
  zone constructor wants to be able to fail if it cannot suballocate an
  mbuf cluster, and the mbuf allocators want to be able to fail in general
  in a MAC kernel if the MAC mbuf initializer fails.  This fixes the
  panics people are seeing when they run out of memory for mbuf clusters.
* Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing
  the default.

Both bmilekic and jeff have reviewed the changes made to make failable
zone allocations work.

1 files changed, 8 insertions, 6 deletions

diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index a83b9e1..a104ae4 100644
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -74,9 +74,9 @@ static void doenterpgrp(struct proc *, struct pgrp *);
 static void orphanpg(struct pgrp *pg);
 static void pgadjustjobc(struct pgrp *pgrp, int entering);
 static void pgdelete(struct pgrp *);
-static void proc_ctor(void *mem, int size, void *arg);
+static int proc_ctor(void *mem, int size, void *arg, int flags);
 static void proc_dtor(void *mem, int size, void *arg);
-static void proc_init(void *mem, int size);
+static int proc_init(void *mem, int size, int flags);
 static void proc_fini(void *mem, int size);
 
 /*
@@ -128,12 +128,13 @@ procinit()
 /*
  * Prepare a proc for use.
  */
-static void
-proc_ctor(void *mem, int size, void *arg)
+static int
+proc_ctor(void *mem, int size, void *arg, int flags)
 {
 	struct proc *p;
 
 	p = (struct proc *)mem;
+	return (0);
 }
 
 /*
@@ -178,8 +179,8 @@ proc_dtor(void *mem, int size, void *arg)
 /*
  * Initialize type-stable parts of a proc (when newly created).
  */
-static void
-proc_init(void *mem, int size)
+static int
+proc_init(void *mem, int size, int flags)
 {
 	struct proc *p;
 	struct thread *td;
@@ -195,6 +196,7 @@ proc_init(void *mem, int size)
 	proc_linkup(p, kg, ke, td);
 	bzero(&p->p_mtx, sizeof(struct mtx));
 	mtx_init(&p->p_mtx, "process lock", NULL, MTX_DEF | MTX_DUPOK);
+	return (0);
 }
 
 /*