Changeset 9a9c805 in mainline

Timestamp:

2012-11-07T10:50:20Z (11 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

5892ec1

Parents:

1107050

Message:

Reserve memory for NORESERVE areas pagefaults when the page fault
happens.

• This way, NORESERVE areas should not contribute to an overcommit situation.

File:

• kernel/generic/src/mm/backend_anon.c (modified) (1 diff)

kernel/generic/src/mm/backend_anon.c

@@ -236 +236 @@
                  */
 
-                unsigned int flags;
-
                 if (area->flags & AS_AREA_NORESERVE) {
                         /*
-                         * This is a NORESERVE area, which means that no
-                         * physical memory has been reserved beforehands.
-                         * We therefore need to make an atomic and reserving
-                         * allocation.
+                         * Reserve the memory for this page now.
                          */
-                        flags = FRAME_ATOMIC;
-                } else {
-                        /*
-                         * The physical memory has already been reserved
-                         * when this part of the area was created. Avoid
-                         * double reservation by using the appropriate flag.
-                         */
-                        flags = FRAME_NO_RESERVE;
+                        if (!reserve_try_alloc(1))
+                                return AS_PF_FAULT;
                 }
 
-                kpage = km_temporary_page_get(&frame, flags);
-                if (!kpage)
-                        return AS_PF_FAULT;
+                kpage = km_temporary_page_get(&frame, FRAME_NO_RESERVE);
                 memsetb((void *) kpage, PAGE_SIZE, 0);
                 km_temporary_page_put(kpage);