Provide basic page cache statistics

* Makefrag.am (EXTRA_DIST): Add kern/gnumach.srv.
(include_mach_HEADERS): Add include/mach/gnumach.defs and
include/mach/vm_cache_statistics.h
(nodist_libkernel_a_SOURCES): Add kern/gnumach.server.defs.c,
kern/gnumach.server.h, kern/gnumach.server.c, kern/gnumach.server.msgids,
kern/gnumach.server.defs.
* include/mach/mach_types.h: Add #include <mach/vm_cache_statistics.h>.
* kern/ipc_kobject.c (ipc_kobject_server): Declare and call
gnumach_server_routine.
* vm/vm_object.c (vm_object_cached_pages): New variable.
(vm_object_cached_pages_lock_data): Likewise.
(vm_object_deallocate): Update number of cached pages.
(vm_object_lookup): Likewise.
(vm_object_lookup_name): Likewise.
(vm_object_destroy): Likewise.
(vm_object_enter): Likewise.
* vm/vm_object.h (ref_count): Declare as int.
(resident_page_count): Likewise.
(vm_object_cached_count): Add extern declaration.
(vm_object_cached_pages): Likewise.
(vm_object_cached_pages_lock_data): Likewise.
(vm_object_cached_pages_update): New macro.
* vm/vm_resident.c (vm_page_insert): Assert resident page count doesn't
overflow, update number of cached pages as appropriate.
(vm_page_replace): Likewise.
(vm_page_remove): Update number of cached pages as appropriate.
* vm/vm_user.c: Add #include <mach/vm_cache_statistics.h>.
(vm_cache_statistics): New function.
* vm/vm_user.h: Add #include <mach/mach_types.h>.
(vm_cache_statistics): New declaration.
* include/mach/gnumach.defs: New file.

9 files changed, 126 insertions, 2 deletions

diff --git a/Makefrag.am b/Makefrag.am
index 7180093..c0cb8fe 100644
--- a/Makefrag.am
+++ b/Makefrag.am
@@ -209,6 +209,7 @@ libkernel_a_SOURCES += \
 EXTRA_DIST += \
 	kern/mach.srv \
 	kern/mach4.srv \
+	kern/gnumach.srv \
 	kern/mach_debug.srv \
 	kern/mach_host.srv
 
@@ -346,6 +347,7 @@ include_mach_HEADERS = \
 	include/mach/exc.defs \
 	include/mach/mach.defs \
 	include/mach/mach4.defs \
+	include/mach/gnumach.defs \
 	include/mach/mach_host.defs \
 	include/mach/mach_port.defs \
 	include/mach/mach_types.defs \
@@ -388,6 +390,7 @@ include_mach_HEADERS = \
 	include/mach/time_value.h \
 	include/mach/version.h \
 	include/mach/vm_attributes.h \
+	include/mach/vm_cache_statistics.h \
 	include/mach/vm_inherit.h \
 	include/mach/vm_param.h \
 	include/mach/vm_prot.h \
@@ -483,6 +486,7 @@ nodist_libkernel_a_SOURCES += \
 nodist_lib_dep_tr_for_defs_a_SOURCES += \
 	kern/mach.server.defs.c \
 	kern/mach4.server.defs.c \
+	kern/gnumach.server.defs.c \
 	kern/mach_debug.server.defs.c \
 	kern/mach_host.server.defs.c
 nodist_libkernel_a_SOURCES += \
@@ -492,6 +496,9 @@ nodist_libkernel_a_SOURCES += \
 	kern/mach4.server.h \
 	kern/mach4.server.c \
 	kern/mach4.server.msgids \
+	kern/gnumach.server.h \
+	kern/gnumach.server.c \
+	kern/gnumach.server.msgids \
 	kern/mach_debug.server.h \
 	kern/mach_debug.server.c \
 	kern/mach_debug.server.msgids \
@@ -500,6 +507,7 @@ nodist_libkernel_a_SOURCES += \
 	kern/mach_host.server.msgids
 #	kern/mach.server.defs
 #	kern/mach4.server.defs
+#	kern/gnumach.server.defs
 #	kern/mach_debug.server.defs
 #	kern/mach_host.server.defs
 
diff --git a/include/mach/gnumach.defs b/include/mach/gnumach.defs
new file mode 100644
index 0000000..7331334
--- /dev/null
+++ b/include/mach/gnumach.defs
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2012 Free Software Foundation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+subsystem
+#if	KERNEL_SERVER
+	  KernelServer
+#endif	/* KERNEL_SERVER */
+#if	KERNEL_USER
+	  KernelUser
+#endif	/* KERNEL_USER */
+		       gnumach 4200;
+
+#include <mach/std_types.defs>
+#include <mach/mach_types.defs>
+
+type vm_cache_statistics_data_t = struct[11] of integer_t;
+
+/*
+ * Return page cache statistics for the host on which the target task
+ * resides.
+ */
+routine vm_cache_statistics(
+		target_task	: vm_task_t;
+	out	vm_cache_stats	: vm_cache_statistics_data_t);
diff --git a/include/mach/mach_types.h b/include/mach/mach_types.h
index f6ceac3..8768482 100644
--- a/include/mach/mach_types.h
+++ b/include/mach/mach_types.h
@@ -52,6 +52,7 @@
 #include <mach/vm_inherit.h>
 #include <mach/vm_prot.h>
 #include <mach/vm_statistics.h>
+#include <mach/vm_cache_statistics.h>
 
 #ifdef	MACH_KERNEL
 #include <kern/task.h>		/* for task_array_t */
diff --git a/kern/ipc_kobject.c b/kern/ipc_kobject.c
index c922d7f..f094b73 100644
--- a/kern/ipc_kobject.c
+++ b/kern/ipc_kobject.c
@@ -152,6 +152,7 @@ ipc_kobject_server(request)
 				device_server_routine(),
 				device_pager_server_routine(),
 				mach4_server_routine();
+				gnumach_server_routine();
 #if	MACH_DEBUG
 	extern mig_routine_t	mach_debug_server_routine();
 #endif
@@ -170,6 +171,7 @@ ipc_kobject_server(request)
 	 || (routine = mach_debug_server_routine(&request->ikm_header)) != 0
 #endif	/* MACH_DEBUG */
 	 || (routine = mach4_server_routine(&request->ikm_header)) != 0
+	 || (routine = gnumach_server_routine(&request->ikm_header)) != 0
 #if	MACH_MACHINE_ROUTINES
 	 || (routine = MACHINE_SERVER_ROUTINE(&request->ikm_header)) != 0
 #endif	/* MACH_MACHINE_ROUTINES */
diff --git a/vm/vm_object.c b/vm/vm_object.c
index f101708..7eae3d7 100644
--- a/vm/vm_object.c
+++ b/vm/vm_object.c
@@ -192,6 +192,15 @@ decl_simple_lock_data(,vm_object_cached_lock_data)
 		simple_unlock(&vm_object_cached_lock_data)
 
 /*
+ *	Number of physical pages referenced by cached objects.
+ *	This counter is protected by its own lock to work around
+ *	lock ordering issues.
+ */
+int		vm_object_cached_pages;
+
+decl_simple_lock_data(,vm_object_cached_pages_lock_data)
+
+/*
  *	Virtual memory objects are initialized from
  *	a template (see vm_object_allocate).
  *
@@ -410,6 +419,7 @@ void vm_object_deallocate(
 			queue_enter(&vm_object_cached_list, object,
 				vm_object_t, cached_list);
 			overflow = (++vm_object_cached_count > vm_object_cached_max);
+			vm_object_cached_pages_update(object->resident_page_count);
 			vm_object_cache_unlock();
 
 			vm_object_deactivate_pages(object);
@@ -1860,6 +1870,7 @@ vm_object_t vm_object_lookup(
 				queue_remove(&vm_object_cached_list, object,
 					     vm_object_t, cached_list);
 				vm_object_cached_count--;
+				vm_object_cached_pages_update(-object->resident_page_count);
 			}
 
 			object->ref_count++;
@@ -1891,6 +1902,7 @@ vm_object_t vm_object_lookup_name(
 				queue_remove(&vm_object_cached_list, object,
 					     vm_object_t, cached_list);
 				vm_object_cached_count--;
+				vm_object_cached_pages_update(-object->resident_page_count);
 			}
 
 			object->ref_count++;
@@ -1927,6 +1939,7 @@ void vm_object_destroy(
 		queue_remove(&vm_object_cached_list, object,
 				vm_object_t, cached_list);
 		vm_object_cached_count--;
+		vm_object_cached_pages_update(-object->resident_page_count);
 	}
 	object->ref_count++;
 
@@ -2080,6 +2093,7 @@ restart:
 			queue_remove(&vm_object_cached_list, object,
 					vm_object_t, cached_list);
 			vm_object_cached_count--;
+			vm_object_cached_pages_update(-object->resident_page_count);
 		}
 		object->ref_count++;
 		vm_object_unlock(object);
diff --git a/vm/vm_object.h b/vm/vm_object.h
index c992570..4e4c949 100644
--- a/vm/vm_object.h
+++ b/vm/vm_object.h
@@ -71,8 +71,8 @@ struct vm_object {
 						 * if internal)
 						 */
 
-	short			ref_count;	/* Number of references */
-	short			resident_page_count;
+	int			ref_count;	/* Number of references */
+	int			resident_page_count;
 						/* number of resident pages */
 
 	struct vm_object	*copy;		/* Object that should receive
@@ -370,4 +370,23 @@ MACRO_END
 #define	vm_object_lock_taken(object)	simple_lock_taken(&(object)->Lock)
 #endif	/* VM_OBJECT_DEBUG */
 
+/*
+ *	Page cache accounting.
+ *
+ *	The number of cached objects and pages can be read
+ *	without holding any lock.
+ */
+
+extern int	vm_object_cached_count;
+
+extern int	vm_object_cached_pages;
+decl_simple_lock_data(extern,vm_object_cached_pages_lock_data)
+
+#define vm_object_cached_pages_update(page_count)			\
+	MACRO_BEGIN							\
+	simple_lock(&vm_object_cached_pages_lock_data);			\
+	vm_object_cached_pages += (page_count);				\
+	simple_unlock(&vm_object_cached_pages_lock_data);		\
+	MACRO_END
+
 #endif	/* _VM_VM_OBJECT_H_ */
diff --git a/vm/vm_resident.c b/vm/vm_resident.c
index ae71a74..581a9c4 100644
--- a/vm/vm_resident.c
+++ b/vm/vm_resident.c
@@ -517,6 +517,10 @@ void vm_page_insert(
 	 */
 
 	object->resident_page_count++;
+	assert(object->resident_page_count >= 0);
+
+	if (object->can_persist && (object->ref_count == 0))
+		vm_object_cached_pages_update(1);
 
 	/*
 	 *	Detect sequential access and inactivate previous page.
@@ -585,6 +589,10 @@ void vm_page_replace(
 				m->tabled = FALSE;
 				object->resident_page_count--;
 
+				if (object->can_persist
+				    && (object->ref_count == 0))
+					vm_object_cached_pages_update(-1);
+
 				/*
 				 * Return page to the free list.
 				 * Note the page is not tabled now, so this
@@ -616,6 +624,10 @@ void vm_page_replace(
 	 */
 
 	object->resident_page_count++;
+	assert(object->resident_page_count >= 0);
+
+	if (object->can_persist && (object->ref_count == 0))
+		vm_object_cached_pages_update(1);
 }
 
 /*
@@ -671,6 +683,9 @@ void vm_page_remove(
 	mem->object->resident_page_count--;
 
 	mem->tabled = FALSE;
+
+	if (mem->object->can_persist && (mem->object->ref_count == 0))
+		vm_object_cached_pages_update(-1);
 }
 
 /*
diff --git a/vm/vm_user.c b/vm/vm_user.c
index 59c2a36..a8ce982 100644
--- a/vm/vm_user.c
+++ b/vm/vm_user.c
@@ -38,6 +38,7 @@
 #include <mach/vm_attributes.h>
 #include <mach/vm_param.h>
 #include <mach/vm_statistics.h>
+#include <mach/vm_cache_statistics.h>
 #include <kern/host.h>
 #include <kern/task.h>
 #include <vm/vm_fault.h>
@@ -189,6 +190,29 @@ kern_return_t vm_statistics(map, stat)
 	return(KERN_SUCCESS);
 }
 
+kern_return_t vm_cache_statistics(
+	vm_map_t			map,
+	vm_cache_statistics_data_t	*stats)
+{
+	if (map == VM_MAP_NULL)
+		return KERN_INVALID_ARGUMENT;
+
+	stats->cache_object_count = vm_object_cached_count;
+	stats->cache_count = vm_object_cached_pages;
+
+	/* XXX Not implemented yet */
+	stats->active_tmp_count = 0;
+	stats->inactive_tmp_count = 0;
+	stats->active_perm_count = 0;
+	stats->inactive_perm_count = 0;
+	stats->dirty_count = 0;
+	stats->laundry_count = 0;
+	stats->writeback_count = 0;
+	stats->slab_count = 0;
+	stats->slab_reclaim_count = 0;
+	return KERN_SUCCESS;
+}
+
 /*
  * Handle machine-specific attributes for a mapping, such
  * as cachability, migrability, etc.
diff --git a/vm/vm_user.h b/vm/vm_user.h
index 3f15e5e..c6f20a8 100644
--- a/vm/vm_user.h
+++ b/vm/vm_user.h
@@ -37,6 +37,7 @@
 
 #include <mach/kern_return.h>
 #include <mach/std_types.h>
+#include <mach/mach_types.h>
 
 extern kern_return_t	vm_allocate(vm_map_t, vm_offset_t *, vm_size_t,
 				    boolean_t);
@@ -46,6 +47,7 @@ extern kern_return_t	vm_inherit(vm_map_t, vm_offset_t, vm_size_t,
 extern kern_return_t	vm_protect(vm_map_t, vm_offset_t, vm_size_t, boolean_t,
 				   vm_prot_t);
 extern kern_return_t	vm_statistics(vm_map_t, vm_statistics_data_t *);
+extern kern_return_t	vm_cache_statistics(vm_map_t, vm_cache_statistics_data_t *);
 extern kern_return_t	vm_read(vm_map_t, vm_address_t, vm_size_t, pointer_t *,
 				vm_size_t *);
 extern kern_return_t	vm_write(vm_map_t, vm_address_t, pointer_t, vm_size_t);