Aren/haiku
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

* B_ANY_KERNEL_BLOCK_ADDRESS now aligns the memory on the next power of two

Browse Source 
value greater or equal its size (actually untested, but at least Haiku
  still boots with these changes :-)).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23563 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Axel Dörfler 2008-01-16 19:09:01 +00:00
parent 13b76705a0
commit abf34addc5
1 changed files with 33 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
src/system/kernel/vm/vm.cpp
View File

@ -955,10 +955,20 @@ find_and_insert_area_slot(vm_address_space *addressSpace, addr_t start,
if (status == B_OK || status == B_BAD_VALUE)
return status;
// there was no reserved area, and the slot doesn't seem to be used already
// There was no reserved area, and the slot doesn't seem to be used
// already
// ToDo: this could be further optimized.
}
size_t alignment = B_PAGE_SIZE;
if (addressSpec == B_ANY_KERNEL_BLOCK_ADDRESS) {
// align the memory to the next power of two of the size
while (alignment < size)
alignment <<= 1;
}
start = ROUNDUP(start, alignment);
// walk up to the spot where we should start searching
second_chance:
next = addressSpace->areas;
@ -981,9 +991,10 @@ second_chance:
// find a hole big enough for a new area
if (!last) {
// see if we can build it at the beginning of the virtual map
if (!next || (next->base >= addressSpace->base + size)) {
if (!next || (next->base >= ROUNDUP(addressSpace->base,
alignment) + size)) {
foundSpot = true;
area->base = addressSpace->base;
area->base = ROUNDUP(addressSpace->base, alignment);
break;
}
last = next;
@ -991,7 +1002,8 @@ second_chance:
}
// keep walking
while (next) {
if (next->base >= last->base + last->size + size) {
if (next->base >= ROUNDUP(last->base + last->size, alignment)
+ size) {
// we found a spot (it'll be filled up below)
break;
}
@ -999,23 +1011,26 @@ second_chance:
next = next->address_space_next;
}
if ((addressSpace->base + (addressSpace->size - 1))
>= (last->base + last->size + (size - 1))) {
if ((addressSpace->base + (addressSpace->size - 1)) >= (ROUNDUP(
last->base + last->size, alignment) + (size - 1))) {
// got a spot
foundSpot = true;
area->base = last->base + last->size;
area->base = ROUNDUP(last->base + last->size, alignment);
break;
} else {
// we didn't find a free spot - if there were any reserved areas with
// the RESERVED_AVOID_BASE flag set, we can now test those for free
// space
// We didn't find a free spot - if there were any reserved areas
// with the RESERVED_AVOID_BASE flag set, we can now test those
// for free space
// ToDo: it would make sense to start with the biggest of them
next = addressSpace->areas;
last = NULL;
for (last = NULL; next; next = next->address_space_next, last = next) {
for (last = NULL; next; next = next->address_space_next,
last = next) {
// ToDo: take free space after the reserved area into account!
if (next->size == size) {
// the reserved area is entirely covered, and thus, removed
if (next->base == ROUNDUP(next->base, alignment)
&& next->size == size) {
// The reserved area is entirely covered, and thus,
// removed
if (last)
last->address_space_next = next->address_space_next;
else
@ -1026,9 +1041,11 @@ second_chance:
free(next);
break;
}
if (next->size >= size) {
// the new area will be placed at the end of the reserved
// area, and the reserved area will be resized to make space
if (next->size - (ROUNDUP(next->base, alignment)
- next->base) >= size) {
// The new area will be placed at the end of the
// reserved area, and the reserved area will be resized
// to make space
foundSpot = true;
next->size -= size;
last = next;