Changeset a55ddc64 in mainline

Timestamp:

2011-11-17T22:29:00Z (12 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

ad12b5ea

Parents:

6b326ea1

Message:

Allocate PTEs from low memory.

• Introduce a dedicated slab cache for pte_t's.
• This should limit the depth of nested page faults.

Location:

kernel/genarch

Files:

• include/mm/page_ht.h (modified) (2 diffs)
• src/mm/as_ht.c (modified) (2 diffs)
• src/mm/page_ht.c (modified) (3 diffs)

kernel/genarch/include/mm/page_ht.h

@@ -43 +43 @@
 #include <mm/as.h>
 #include <mm/page.h>
+#include <mm/slab.h>
 #include <synch/mutex.h>
 #include <adt/hash_table.h>
@@ -64 +65 @@
 extern page_mapping_operations_t ht_mapping_operations;
 
+extern slab_cache_t *pte_cache;
 extern mutex_t page_ht_lock;
 extern hash_table_t page_ht;

kernel/genarch/src/mm/as_ht.c

@@ -41 +41 @@
 #include <mm/as.h>
 #include <mm/frame.h>
+#include <mm/slab.h>
 #include <typedefs.h>
 #include <memstr.h>
@@ -77 +78 @@
                 hash_table_create(&page_ht, PAGE_HT_ENTRIES, 2, &ht_operations);
                 mutex_initialize(&page_ht_lock, MUTEX_PASSIVE);
+                pte_cache = slab_cache_create("pte_cache", sizeof(pte_t), 0, NULL, NULL,
+                    SLAB_CACHE_MAGDEFERRED);
         }
         

kernel/genarch/src/mm/page_ht.c

@@ -60 +60 @@
 static pte_t *ht_mapping_find(as_t *, uintptr_t, bool);
 
+slab_cache_t *pte_cache = NULL;
+
 /**
  * This lock protects the page hash table. It must be acquired
@@ -163 +165 @@
         pte_t *pte = hash_table_get_instance(item, pte_t, link);
         
-        free(pte);
+        slab_free(pte_cache, pte);
 }
 
@@ -188 +190 @@
         
         if (!hash_table_find(&page_ht, key)) {
-                pte_t *pte = (pte_t *) malloc(sizeof(pte_t), FRAME_ATOMIC);
+                pte_t *pte = slab_alloc(pte_cache, FRAME_LOWMEM | FRAME_ATOMIC);
                 ASSERT(pte != NULL);