Changeset 9dd730d1 in mainline

Timestamp:

2011-04-16T12:40:22Z (13 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

8a2474f

Parents:

8b655705

Message:

Reserve only anonymous pages in ELF-backed address space areas.

File:

• kernel/generic/src/mm/backend_elf.c (modified) (3 diffs)

kernel/generic/src/mm/backend_elf.c

@@ -72 +72 @@
 bool elf_create(as_area_t *area)
 {
+        elf_segment_header_t *entry = area->backend_data.segment;
+        size_t nonanon_pages = ALIGN_DOWN(entry->p_filesz, PAGE_SIZE);
+
         /**
          * @todo:
@@ -77 +80 @@
          * supporting structures allocated during the page fault.
          */
-        return reserve_try_alloc(area->pages);
+        
+        if (area->pages <= nonanon_pages)
+                return true;
+        
+        return reserve_try_alloc(area->pages - nonanon_pages);
 }
 
 bool elf_resize(as_area_t *area, size_t new_pages)
 {
-        if (new_pages > area->pages)
-                return reserve_try_alloc(new_pages - area->pages);
-        else if (new_pages < area->pages)
-                reserve_free(area->pages - new_pages);
+        elf_segment_header_t *entry = area->backend_data.segment;
+        size_t nonanon_pages = ALIGN_DOWN(entry->p_filesz, PAGE_SIZE);
+
+        if (new_pages > area->pages) {
+                /* The area is growing. */
+                if (area->pages >= nonanon_pages)
+                        return reserve_try_alloc(new_pages - area->pages);
+                else if (new_pages > nonanon_pages)
+                        return reserve_try_alloc(new_pages - nonanon_pages);
+        } else if (new_pages < area->pages) {
+                /* The area is shrinking. */
+                if (new_pages >= nonanon_pages)
+                        reserve_free(area->pages - new_pages);
+                else if (area->pages > nonanon_pages)
+                        reserve_free(nonanon_pages - new_pages);
+        }
         
         return true;
@@ -180 +199 @@
 void elf_destroy(as_area_t *area)
 {
-        /**
-         * @todo:
-         * Unreserve only how much was really reserved.
-         */
-        reserve_free(area->pages);
+        elf_segment_header_t *entry = area->backend_data.segment;
+        size_t nonanon_pages = ALIGN_DOWN(entry->p_filesz, PAGE_SIZE);
+
+        if (area->pages > nonanon_pages)
+                reserve_free(area->pages - nonanon_pages);
 }