Bananymous/banan-os
1
1
Fork 1
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

LibC: Fix malloc bitmap allocator allocation

Browse Source 
Use full pages for bitmap allocators and fix the capacity extension
condition
This commit is contained in:
Bananymous
2026-07-01 12:55:44 +03:00
parent d241975ce1
commit 74e94eedae
1 changed files with 6 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
userspace/libraries/LibC/malloc.cpp
View File

@@ -238,8 +238,6 @@ void* malloc(size_t total_size)
return &header + 1; return &header + 1;
} }
constexpr size_t allocators_per_page = PAGE_SIZE / sizeof(BitmapAllocator);
void* result = nullptr; void* result = nullptr;
pthread_mutex_lock(&s_allocator_lock); pthread_mutex_lock(&s_allocator_lock);
@@ -248,9 +246,12 @@ void* malloc(size_t total_size)
if ((result = s_allocators[i].allocate(total_size))) if ((result = s_allocators[i].allocate(total_size)))
goto malloc_return; goto malloc_return;
if (s_allocator_capacity % allocators_per_page == 0) if (s_allocator_count == s_allocator_capacity)
{ {
void* new_allocators = mmap(nullptr, (s_allocator_capacity + allocators_per_page) * sizeof(BitmapAllocator), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); const size_t allocator_pages = (s_allocator_capacity * sizeof(BitmapAllocator) + PAGE_SIZE - 1) / PAGE_SIZE;
const size_t new_allocator_pages = allocator_pages + 1;
void* new_allocators = mmap(nullptr, new_allocator_pages * PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
if (new_allocators == MAP_FAILED) if (new_allocators == MAP_FAILED)
goto malloc_return; goto malloc_return;
@@ -260,7 +261,7 @@ void* malloc(size_t total_size)
munmap(s_allocators, s_allocator_capacity * sizeof(BitmapAllocator)); munmap(s_allocators, s_allocator_capacity * sizeof(BitmapAllocator));
s_allocators = static_cast<BitmapAllocator*>(new_allocators); s_allocators = static_cast<BitmapAllocator*>(new_allocators);
s_allocator_capacity = s_allocator_capacity + allocators_per_page; s_allocator_capacity = new_allocator_pages * PAGE_SIZE / sizeof(BitmapAllocator);
} }
if (!s_allocators[s_allocator_count].initialize()) if (!s_allocators[s_allocator_count].initialize())