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Kernel: Implement kmalloc_good_size for the new kmalloc

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This lets kmalloc-aware data structures like Vector and HashTable use
up the extra wasted space we allocate in the slab heaps & heap chunks.
This commit is contained in:
Idan Horowitz 2022-03-07 23:38:05 +02:00
parent c204885a94
commit 29eee390ec
2 changed files with 10 additions and 1 deletions
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2
Kernel/Heap/Heap.h
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@ -44,6 +44,8 @@ class Heap {
}
public:
static constexpr size_t AllocationHeaderSize = sizeof(AllocationHeader);
Heap(u8* memory, size_t memory_size)
: m_total_chunks(calculate_chunks(memory_size))
, m_chunks(memory)

9
Kernel/Heap/kmalloc.cpp
View file

@ -22,6 +22,7 @@ static constexpr size_t CHUNK_SIZE = 32;
#else
static constexpr size_t CHUNK_SIZE = 64;
#endif
static_assert(is_power_of_two(CHUNK_SIZE));
static constexpr size_t INITIAL_KMALLOC_MEMORY_SIZE = 2 * MiB;
@ -435,7 +436,13 @@ void kfree_sized(void* ptr, size_t size)
size_t kmalloc_good_size(size_t size)
{
return size;
VERIFY(size > 0);
// NOTE: There's no need to take the kmalloc lock, as the kmalloc slab-heaps (and their sizes) are constant
for (auto const& slabheap : g_kmalloc_global->slabheaps) {
if (size <= slabheap.slab_size())
return slabheap.slab_size();
}
return round_up_to_power_of_two(size + Heap<CHUNK_SIZE>::AllocationHeaderSize, CHUNK_SIZE) - Heap<CHUNK_SIZE>::AllocationHeaderSize;
}
void* kmalloc_aligned(size_t size, size_t alignment)