ipc: replace the IPC table with a radix tree

Currently, the port names are mapped to an IPC object (e.g. a port)
using a table.  This, however, requires large chunks of continuous
memory, and leads to scalability problems as virtual kernel memory is
a scarce resource.  To avoid excessive overhead, non-contiguous port
names are spilled into a splay tree.

Replace the IPC table with a radix tree.  As the radix tree is able to
store non-contiguous names with reasonable overhead, we can drop the
splay tree as well.

* ipc/ipc_entry.c (ipc_entry_tree_collision): Remove function.
(ipc_entry_cache): New variable.
(ipc_entry_lookup): Replace with a radix tree lookup.
(ipc_entry_get): The free list handling is changed a little.  Adopt
accordingly.
(ipc_entry_free_name): New function.
(ipc_entry_alloc): Adopt accordingly.
(ipc_entry_alloc_name): Likewise.
(ipc_entry_dealloc): Likewise.
(ipc_entry_grow_table): Remove function.
* ipc/ipc_entry.h (struct ipc_entry): Update comment, add field for
name and free list, remove unused fields.
(ipc_entry_cache, ie_alloc, ie_free): New declarations.
(struct ipc_tree_entry): Remove.  Also remove any related declarations.
(ipc_entry_grow_table): Remove declaration.
* ipc/ipc_init.c (ipc_bootstrap): Adopt initialization.
* ipc/ipc_kmsg.c (ipc_kmsg_copyout_header): Use `ipc_entry_alloc'
instead of re-coding it.  Adopt free list handling.
(ipc_kmsg_copyout_object): Adopt free list handling, store the name.
* ipc/ipc_object.c (ipc_object_copyout): Likewise.
(ipc_object_copyout_multiname): Likewise.
* ipc/ipc_space.c (ipc_space_create): Initialize radix tree and free list.
Drop table and splay tree initialization.
(ipc_space_destroy): Free ipc entries and radix tree, remove table and
splay tree cleanup.
* ipc/ipc_space.h (struct ipc_space): Add radix tree, free list, and size.
Remove all fields related to the table and splay tree.
* ddb/db_print.c (db_port_iterate): Adopt iteration.
(db_lookup_port): Adopt lookup.
* include/mach_debug/ipc_info.h: Remove unused parts of the debug interface.
* include/mach_debug/mach_debug.defs: Likewise.
* include/mach_debug/mach_debug_types.defs: Likewise.
* ipc/mach_debug.c: Likewise.
* ipc/ipc_right.c (ipc_right_reverse): Adopt lookup, store name.
(ipc_right_check): Adopt removal.
(ipc_right_destroy): Likewise.
(ipc_right_dealloc): Likewise.
(ipc_right_delta): Likewise.
(ipc_right_copyin): Adopt insertion, adopt removal.
(ipc_right_copyin_two): Adopt removal.
(ipc_right_copyout): Adopt insertion, adopt removal.
(ipc_right_rename): Likewise, also update comment.
* ipc/mach_port.c (mach_port_names): Adopt iteration.
(mach_port_get_set_status): Likewise.
* ipc/port.h: Update comment.
* ipc/ipc_hash.c: Delete file.
* ipc/ipc_hash.h: Likewise.
* ipc/ipc_splay.c: Likewise.
* ipc/ipc_splay.h: Likewise.
* Makefrag.am (libkernel_a_SOURCES): Remove these files.

1 files changed, 2 insertions, 4 deletions

diff --git a/ipc/ipc_init.c b/ipc/ipc_init.c
index debda47..2c58a6e 100644
--- a/ipc/ipc_init.c
+++ b/ipc/ipc_init.c
@@ -47,7 +47,6 @@
 #include <ipc/ipc_marequest.h>
 #include <ipc/ipc_notify.h>
 #include <ipc/ipc_kmsg.h>
-#include <ipc/ipc_hash.h>
 #include <ipc/ipc_init.h>
 
 
@@ -76,8 +75,8 @@ ipc_bootstrap(void)
 	kmem_cache_init(&ipc_space_cache, "ipc_space",
 			sizeof(struct ipc_space), 0, NULL, NULL, NULL, 0);
 
-	kmem_cache_init(&ipc_tree_entry_cache, "ipc_tree_entry",
-			sizeof(struct ipc_tree_entry), 0, NULL, NULL, NULL, 0);
+	kmem_cache_init(&ipc_entry_cache, "ipc_entry",
+			sizeof(struct ipc_entry), 0, NULL, NULL, NULL, 0);
 
 	kmem_cache_init(&ipc_object_caches[IOT_PORT], "ipc_port",
 			sizeof(struct ipc_port), 0, NULL, NULL, NULL, 0);
@@ -97,7 +96,6 @@ ipc_bootstrap(void)
 
 	ipc_table_init();
 	ipc_notify_init();
-	ipc_hash_init();
 	ipc_marequest_init();
 }