Implement global and per-uid accounting of the anonymous memory. Add

rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved
for the uid.

The accounting information (charge) is associated with either map entry,
or vm object backing the entry, assuming the object is the first one
in the shadow chain and entry does not require COW. Charge is moved
from entry to object on allocation of the object, e.g. during the mmap,
assuming the object is allocated, or on the first page fault on the
entry. It moves back to the entry on forks due to COW setup.

The per-entry granularity of accounting makes the charge process fair
for processes that change uid during lifetime, and decrements charge
for proper uid when region is unmapped.

The interface of vm_pager_allocate(9) is extended by adding struct ucred *,
that is used to charge appropriate uid when allocation if performed by
kernel, e.g. md(4).

Several syscalls, among them is fork(2), may now return ENOMEM when
global or per-uid limits are enforced.

In collaboration with:	pho
Reviewed by:	alc
Approved by:	re (kensmith)

1 files changed, 8 insertions, 0 deletions

diff --git a/sys/sys/priv.h b/sys/sys/priv.h
index 97eb9cc..a964c2f 100644
--- a/sys/sys/priv.h
+++ b/sys/sys/priv.h
@@ -283,6 +283,14 @@
 #define	PRIV_VM_MADV_PROTECT	360	/* Can set MADV_PROTECT. */
 #define	PRIV_VM_MLOCK		361	/* Can mlock(), mlockall(). */
 #define	PRIV_VM_MUNLOCK		362	/* Can munlock(), munlockall(). */
+#define	PRIV_VM_SWAP_NOQUOTA	363	/*
+					 * Can override the global
+					 * swap reservation limits.
+					 */
+#define	PRIV_VM_SWAP_NORLIMIT	364	/*
+					 * Can override the per-uid
+					 * swap reservation limits.
+					 */
 
 /*
  * Device file system privileges.