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

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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
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49
src/system/kernel/vm/vm.cpp
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@ -955,10 +955,20 @@ find_and_insert_area_slot(vm_address_space *addressSpace, addr_t start,
if (status == B_OK || status == B_BAD_VALUE) if (status == B_OK || status == B_BAD_VALUE)
return status; 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. // 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 // walk up to the spot where we should start searching
second_chance: second_chance:
next = addressSpace->areas; next = addressSpace->areas;
@ -981,9 +991,10 @@ second_chance:
// find a hole big enough for a new area // find a hole big enough for a new area
if (!last) { if (!last) {
// see if we can build it at the beginning of the virtual map // 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; foundSpot = true;
area->base = addressSpace->base; area->base = ROUNDUP(addressSpace->base, alignment);
break; break;
} }
last = next; last = next;
@ -991,7 +1002,8 @@ second_chance:
} }
// keep walking // keep walking
while (next) { 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) // we found a spot (it'll be filled up below)
break; break;
} }
@ -999,23 +1011,26 @@ second_chance:
next = next->address_space_next; next = next->address_space_next;
} }
if ((addressSpace->base + (addressSpace->size - 1)) if ((addressSpace->base + (addressSpace->size - 1)) >= (ROUNDUP(
>= (last->base + last->size + (size - 1))) { last->base + last->size, alignment) + (size - 1))) {
// got a spot // got a spot
foundSpot = true; foundSpot = true;
area->base = last->base + last->size; area->base = ROUNDUP(last->base + last->size, alignment);
break; break;
} else { } else {
// we didn't find a free spot - if there were any reserved areas with // We didn't find a free spot - if there were any reserved areas
// the RESERVED_AVOID_BASE flag set, we can now test those for free // with the RESERVED_AVOID_BASE flag set, we can now test those
// space // for free space
// ToDo: it would make sense to start with the biggest of them // ToDo: it would make sense to start with the biggest of them
next = addressSpace->areas; next = addressSpace->areas;
last = NULL; 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! // ToDo: take free space after the reserved area into account!
if (next->size == size) { if (next->base == ROUNDUP(next->base, alignment)
// the reserved area is entirely covered, and thus, removed && next->size == size) {
// The reserved area is entirely covered, and thus,
// removed
if (last) if (last)
last->address_space_next = next->address_space_next; last->address_space_next = next->address_space_next;
else else
@ -1026,9 +1041,11 @@ second_chance:
free(next); free(next);
break; break;
} }
if (next->size >= size) { if (next->size - (ROUNDUP(next->base, alignment)
// the new area will be placed at the end of the reserved - next->base) >= size) {
// area, and the reserved area will be resized to make space // 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; foundSpot = true;
next->size -= size; next->size -= size;
last = next; last = next;