vasilito/RedBear-OS
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Keep track of last free page

Browse Source
This commit is contained in:
Jeremy Soller
2020-09-09 20:19:28 -06:00
parent f17a1b52bd
commit a12be1b172
1 changed files with 30 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/allocator/frame/buddy.rs
+30 -6
View File
@@ -34,7 +34,7 @@ impl BuddyEntry {
#[repr(packed)]
struct BuddyMapFooter {
next: PhysicalAddress,
//TODO: index of last known free bit
skip: usize,
}
pub struct BuddyAllocator<A> {
@@ -104,6 +104,7 @@ impl<A: Arch> BuddyAllocator<A> {
let map_virt = A::phys_to_virt(map_phys);
A::write(map_virt.add(Self::MAP_PAGE_BYTES), BuddyMapFooter {
next: entry.map,
skip: Self::MAP_PAGE_BYTES,
});
entry.map = map_phys;
}
@@ -151,7 +152,11 @@ impl<A: Arch> FrameAllocator for BuddyAllocator<A> {
let mut offset = start_offset;
'find: while map_phys.data() != 0 {
let map_virt = A::phys_to_virt(map_phys);
for i in 0 .. Self::MAP_PAGE_BYTES {
let footer_virt = map_virt.add(Self::MAP_PAGE_BYTES);
let mut footer = A::read::<BuddyMapFooter>(footer_virt);
offset += footer.skip * A::PAGE_SIZE * 8;
for i in footer.skip .. Self::MAP_PAGE_BYTES {
let map_byte_virt = map_virt.add(i);
let value: u8 = A::read(map_byte_virt);
if (value & u8::MAX) != 0 {
@@ -166,19 +171,31 @@ impl<A: Arch> FrameAllocator for BuddyAllocator<A> {
}
found += 1;
if found == count.data() {
// If skip is set to the start of the newly allocated frames
if footer.skip == start_i && footer.skip != i {
// Set it to the end of the newly allocated frames
footer.skip = i;
A::write(footer_virt, footer);
}
break 'find;
}
} else {
found = 0;
}
}
} else {
// If skip is set to the current 8 frames, and they are already used
if footer.skip == i {
// Set skip to the next current frame
footer.skip = i + 1;
A::write(footer_virt, footer);
}
found = 0;
}
offset += A::PAGE_SIZE * 8;
}
let footer = A::read::<BuddyMapFooter>(map_virt.add(Self::MAP_PAGE_BYTES));
map_phys = footer.next;
}
@@ -217,7 +234,8 @@ impl<A: Arch> FrameAllocator for BuddyAllocator<A> {
}
start_i = 0;
let footer = A::read::<BuddyMapFooter>(map_virt.add(Self::MAP_PAGE_BYTES));
let footer_virt = map_virt.add(Self::MAP_PAGE_BYTES);
let footer = A::read::<BuddyMapFooter>(footer_virt);
map_phys = footer.next;
}
}
@@ -247,14 +265,20 @@ impl<A: Arch> FrameAllocator for BuddyAllocator<A> {
loop {
if map_phys.data() == 0 { unimplemented!("map_phys.data() == 0") }
let map_virt = A::phys_to_virt(map_phys);
let footer_virt = map_virt.add(Self::MAP_PAGE_BYTES);
let mut footer = A::read::<BuddyMapFooter>(footer_virt);
if map_page == 0 {
let map_byte_virt = map_virt.add(map_bit / 8);
let map_byte = map_bit / 8;
if map_byte < footer.skip {
footer.skip = map_byte;
A::write(footer_virt, footer);
}
let map_byte_virt = map_virt.add(map_byte);
let mut value: u8 = A::read(map_byte_virt);
value |= 1 << (map_bit % 8);
A::write(map_byte_virt, value);
break;
} else {
let footer = A::read::<BuddyMapFooter>(map_virt.add(Self::MAP_PAGE_BYTES));
map_phys = footer.next;
map_page -= 1;
}