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Kernel/MM: Don't allocate a temporary Vector when parsing the memory map

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Instead we can achieve the same by just using an optional.
This commit is contained in:
Hendiadyoin1 2024-01-12 00:03:49 +01:00 • committed by Andrew Kaster
parent adac43ab1c
commit 23d6c88027
1 changed files with 16 additions and 9 deletions
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25
Kernel/Memory/MemoryManager.cpp
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@ -295,8 +295,7 @@ UNMAP_AFTER_INIT void MemoryManager::parse_memory_map()
PhysicalAddress upper;
};
Vector<ContiguousPhysicalVirtualRange> contiguous_physical_ranges;
Optional<ContiguousPhysicalVirtualRange> last_contiguous_physical_range;
for (auto* mmap = mmap_begin; mmap < mmap_end; mmap++) {
// We have to copy these onto the stack, because we take a reference to these when printing them out,
// and doing so on a packed struct field is UB.
@ -364,6 +363,8 @@ UNMAP_AFTER_INIT void MemoryManager::parse_memory_map()
continue;
}
// FIXME: This might have a nicer solution than slicing the ranges apart,
// to just put them back together when we dont find a used range in them
for (PhysicalSize page_base = address; page_base <= (address + length); page_base += PAGE_SIZE) {
auto addr = PhysicalAddress(page_base);
@ -372,24 +373,30 @@ UNMAP_AFTER_INIT void MemoryManager::parse_memory_map()
for (auto& used_range : global_data.used_memory_ranges) {
if (addr.get() >= used_range.start.get() && addr.get() <= used_range.end.get()) {
should_skip = true;
page_base = used_range.end.get();
break;
}
}
if (should_skip)
continue;
if (contiguous_physical_ranges.is_empty() || contiguous_physical_ranges.last().upper.offset(PAGE_SIZE) != addr) {
contiguous_physical_ranges.append(ContiguousPhysicalVirtualRange {
.lower = addr,
.upper = addr,
});
if (!last_contiguous_physical_range.has_value() || last_contiguous_physical_range->upper.offset(PAGE_SIZE) != addr) {
if (last_contiguous_physical_range.has_value()) {
auto range = last_contiguous_physical_range.release_value();
// FIXME: OOM?
global_data.physical_regions.append(PhysicalRegion::try_create(range.lower, range.upper).release_nonnull());
}
last_contiguous_physical_range = ContiguousPhysicalVirtualRange { .lower = addr, .upper = addr };
} else {
contiguous_physical_ranges.last().upper = addr;
last_contiguous_physical_range->upper = addr;
}
}
}
for (auto& range : contiguous_physical_ranges) {
// FIXME: If this is ever false, theres a good chance that all physical memory is already spent
if (last_contiguous_physical_range.has_value()) {
auto range = last_contiguous_physical_range.release_value();
// FIXME: OOM?
global_data.physical_regions.append(PhysicalRegion::try_create(range.lower, range.upper).release_nonnull());
}