重写 buddy 分配器与内存统计机制, 增加页引用计数机制.

Author: xiaoyi1212

src/arch/x86_64/task/sched_x64.c

@@ -70,19 +70,22 @@ void calibrate_tsc_with_hpet() {
     uint64_t ns_end    = nano_time();
     uint64_t delta_tsc = tsc_end - tsc_start;
     uint64_t delta_ns  = ns_end - ns_start;
-    if (delta_tsc == 0 || delta_ns == 0)
+    if (delta_tsc == 0 || delta_ns == 0) {
         return;
+    }
     arch_current_cpu()->arch_data.tsc_conv_shift = 22;
     arch_current_cpu()->arch_data.tsc_conv_mul =
         (uint32_t)((delta_ns << arch_current_cpu()->arch_data.tsc_conv_shift) / delta_tsc);
     arch_current_cpu()->arch_data.tsc_base_tsc = read_tsc();
     arch_current_cpu()->arch_data.tsc_base_ns  = nano_time();
     uint64_t freq_hz                           = (delta_tsc * 1000000000ull) / delta_ns;
-    if (is_bsp)
+    if (is_bsp) {
         kinfo("Estimated TSC frequency: %llu MHz", freq_hz / 1000 / 1000);
+    }
 end:
-    if (is_bsp)
+    if (is_bsp) {
         kinfo("%s clock time %llu", cpu_has_rdtsc() ? "TSC" : "HPET", sched_clock());
+    }
     spin_unlock(tsc_lock);
 }
 

src/include/mem/bitmap.h

@@ -20,3 +20,5 @@ void bitmap_set_range(Bitmap *bitmap, size_t start, size_t end, bool value);
 size_t bitmap_find_range(Bitmap *bitmap, size_t length, bool value);
 
 size_t bitmap_find_range_from(Bitmap *bitmap, size_t length, bool value, size_t start_from);
+
+Bitmap *get_usable_regions();

src/include/mem/buddy.h

@@ -1,274 +1,67 @@
 #pragma once
 
-#define MAX_ORDER 20
+#define MAX_ORDER 31
+#define MIN_ORDER 12 // 4KB = 2^12
+#define ORDER_COUNT (MAX_ORDER - MIN_ORDER)
 
-// Zone 边界（物理地址）
-#define ZONE_DMA_END   (16UL << 20) // 16MB
-#define ZONE_DMA32_END (4UL << 30)  // 4GB
+// Zone 边界
+#define ZONE_DMA_END (16UL << 20)  // 16MB
+#define ZONE_DMA32_END (4UL << 30) // 4GB
 
-#define GFP_DMA    (1 << 0) // 必须从 ZONE_DMA 分配
-#define GFP_DMA32  (1 << 1) // 可以从 ZONE_DMA32 分配
-#define GFP_KERNEL (1 << 2) // 内核普通分配
-#define GFP_ATOMIC (1 << 3) // 原子分配，不能睡眠
-#define GFP_NOWAIT (1 << 4) // 不等待，快速失败
+// GFP 标志
+#define GFP_DMA (1 << 0)
+#define GFP_DMA32 (1 << 1)
+#define GFP_KERNEL (1 << 2)
+#define GFP_ATOMIC (1 << 3)
+#define GFP_NOWAIT (1 << 4)
 
-// 常用组合
 #define GFP_KERNEL_NORMAL (GFP_KERNEL)
-#define GFP_KERNEL_DMA    (GFP_KERNEL | GFP_DMA)
-#define GFP_KERNEL_DMA32  (GFP_KERNEL | GFP_DMA32)
-
-#define PG_reserved 0
-#define PG_slab     1
-#define PG_buddy    2
-#define PG_compound 3
-#define PG_head     4
-#define PG_dirty    5
-#define PG_lru      6
-
-#define PCPU_CACHE_LOW  4
-#define PCPU_CACHE_HIGH 32
-#define PCPU_BATCH      8
-
-// 页面标志操作
-#define PageBuddy(page)      test_bit(PG_buddy, &(page)->flags)
-#define SetPageBuddy(page)   set_bit(PG_buddy, &(page)->flags)
-#define ClearPageBuddy(page) clear_bit(PG_buddy, &(page)->flags)
-
-#define PageCompound(page)      test_bit(PG_compound, &(page)->flags)
-#define SetPageCompound(page)   set_bit(PG_compound, &(page)->flags)
-#define ClearPageCompound(page) clear_bit(PG_compound, &(page)->flags)
-
-#define PageHead(page)      test_bit(PG_head, &(page)->flags)
-#define SetPageHead(page)   set_bit(PG_head, &(page)->flags)
-#define ClearPageHead(page) clear_bit(PG_head, &(page)->flags)
-
-#define PageReserved(page)      test_bit(PG_reserved, &(page)->flags)
-#define SetPageReserved(page)   set_bit(PG_reserved, &(page)->flags)
-#define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags)
-
-#define pfn_to_page(pfn)   (&mem_map[(pfn) - min_pfn])
-#define page_to_pfn(page)  ((uint64_t)((page) - mem_map) + min_pfn)
-#define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT)
-#define phys_to_page(phys) pfn_to_page((phys) >> PAGE_SHIFT)
-#define virt_to_page(virt) phys_to_page(virt_to_phys(virt))
-#define page_to_virt(page) phys_to_virt(page_to_phys(page))
+#define GFP_KERNEL_DMA (GFP_KERNEL | GFP_DMA)
+#define GFP_KERNEL_DMA32 (GFP_KERNEL | GFP_DMA32)
 
 #include "lock.h"
 #include "types.h"
 
+typedef struct buddy_allocator {
+    uintptr_t free_area[ORDER_COUNT];
+    spin_t lock;
+} buddy_allocator_t;
+
 enum zone_type {
 #if defined(__x86_64__)
-    ZONE_DMA, // 0-16MB，用于传统 ISA DMA
+    ZONE_DMA, // 0-16MB
 #endif
-    ZONE_DMA32,  // 0-4GB，用于 32 位 DMA
-    ZONE_NORMAL, // 正常内存
+    ZONE_DMA32,  // 0-4GB
+    ZONE_NORMAL, // 4GB+
     __MAX_NR_ZONES
 };
 
-extern const char *zone_names[__MAX_NR_ZONES];
-
-enum zone_type pfn_to_zone_type(uint64_t pfn);
-
-typedef struct {
-    volatile int counter;
-} atomic_t;
-
-static inline void atomic_set(atomic_t *v, int i) {
-    v->counter = i;
-}
-
-static inline int atomic_read(atomic_t *v) {
-    return v->counter;
-}
-
-static inline void atomic_inc(atomic_t *v) {
-    __sync_add_and_fetch(&v->counter, 1);
-}
-
-static inline int atomic_dec_and_test(atomic_t *v) {
-    return __sync_sub_and_fetch(&v->counter, 1) == 0;
-}
-
-static inline void atomic_add(int i, atomic_t *v) {
-    __sync_add_and_fetch(&v->counter, i);
-}
-
-static inline void atomic_sub(int i, atomic_t *v) {
-    __sync_sub_and_fetch(&v->counter, i);
-}
-
-typedef struct page {
-    atomic_t _refcount;
-    uint64_t flags;
-
-    union {
-        struct {
-            struct page *next;
-            struct page *prev;
-        } lru;
-        struct {
-            void *private;
-        };
-    };
-
-    unsigned char order;
-    uint32_t compound_nr;
-
-    // 新增：所属的 zone
-    unsigned char zone_id;
-
-    uint32_t magic;
-} page_t;
-
-#define PAGE_MAGIC 0xDEADBEEF
-
-enum zone_stat_item {
-    NR_FREE_PAGES,  // 空闲页数
-    NR_ALLOC_PAGES, // 已分配页数
-    NR_ACTIVE,      // 活跃页数
-    NR_INACTIVE,    // 非活跃页数
-    NR_ZONE_STATS
-};
-
-typedef struct zone_stats {
-    atomic_t count[NR_ZONE_STATS];
-} zone_stats_t;
-
-typedef struct free_area {
-    struct page *free_list;
-    uint64_t nr_free;
-} free_area_t;
-
-typedef struct per_cpu_pages {
-    struct page *pages[PCPU_CACHE_HIGH];
-    int count;
-    int low;   // 低水位
-    int high;  // 高水位
-    int batch; // 批量操作数量
-
-    uint64_t alloc_hits;
-    uint64_t alloc_misses;
-    uint64_t free_hits;
-    uint64_t free_misses;
-} per_cpu_pages_t;
-
+// Zone 结构
 typedef struct zone {
-    // Buddy 分配器
-    free_area_t free_area[MAX_ORDER];
-
-    // Zone 范围
+    buddy_allocator_t allocator;
     uint64_t zone_start_pfn;
     uint64_t zone_end_pfn;
-    uint64_t spanned_pages; // 跨越的页数（包括空洞）
-    uint64_t present_pages; // 物理存在的页数
-    uint64_t managed_pages; // 可管理的页数
-
-    // Zone 类型
+    uint64_t managed_pages;
+    uint64_t free_pages;
     enum zone_type type;
     const char *name;
-
-    // 统计信息
-    zone_stats_t vm_stat;
-
-    // Per-CPU 页面缓存（每个CPU一个）
-    per_cpu_pages_t *per_cpu_pageset;
-
-    // 锁
-    spin_t lock;
-
-    // 链表节点（用于遍历所有zone）
-    struct zone *next;
 } zone_t;
 
-typedef struct zonelist {
-    zone_t *zones[__MAX_NR_ZONES]; // 按优先级排序的 zone 列表
-    int nr_zones;                  // zone 数量
-} zonelist_t;
-
-extern page_t *mem_map;
-extern uint64_t max_pfn;
-extern uint64_t min_pfn;
 extern zone_t *zones[__MAX_NR_ZONES];
 extern int nr_zones;
-
-// 获取页面所属的 zone
-#define page_zone(page) (zones[(page)->zone_id])
-
-static inline void set_bit(int nr, volatile uint64_t *addr) {
-    *addr |= (1UL << nr);
-}
-
-static inline void clear_bit(int nr, volatile uint64_t *addr) {
-    *addr &= ~(1UL << nr);
-}
-
-static inline int test_bit(int nr, const volatile uint64_t *addr) {
-    return (*addr >> nr) & 1;
-}
-
-// 引用计数操作
-static inline int page_ref_count(page_t *page) {
-    return atomic_read(&page->_refcount);
-}
-
-static inline void set_page_refcounted(page_t *page) {
-    atomic_set(&page->_refcount, 1);
-}
-
-static inline void get_page(page_t *page) {
-    atomic_inc(&page->_refcount);
-}
-
-static inline bool put_page_testzero(page_t *page) {
-    return atomic_dec_and_test(&page->_refcount);
-}
-
-// 复合页操作
-static inline void set_compound_order(page_t *page, uint32_t order) {
-    page->order       = order;
-    page->compound_nr = 1U << order;
-}
-
-static inline uint32_t compound_order(page_t *page) {
-    if (!PageHead(page))
-        return 0;
-    return page->order;
-}
-
-// Zone 统计操作
-static inline void zone_page_state_add(long delta, zone_t *zone, enum zone_stat_item item) {
-    atomic_add(delta, &zone->vm_stat.count[item]);
-}
-
-static inline uint64_t zone_page_state(zone_t *zone, enum zone_stat_item item) {
-    return atomic_read(&zone->vm_stat.count[item]);
-}
+extern const char *zone_names[__MAX_NR_ZONES];
 
 // 初始化
-void zones_init(uint64_t memory_size);
+void buddy_init(void);
 void add_memory_region(uintptr_t start, uintptr_t end, enum zone_type type);
-void percpu_pagecache_init();
-
-// 分配（多 zone 版本）
-page_t *alloc_pages(uint32_t gfp_flags, uint32_t order);
-#define alloc_page(gfp) alloc_pages(gfp, 0)
 
-// 兼容接口（默认从 NORMAL zone）
-#define __alloc_pages(order) alloc_pages(GFP_KERNEL, order)
-#define __alloc_page()       alloc_pages(GFP_KERNEL, 0)
+// 分配/释放（底层接口）
+uintptr_t buddy_alloc_zone(zone_t *zone, size_t count);
+void buddy_free_zone(zone_t *zone, uintptr_t addr, size_t order);
 
-// 释放
-void __free_pages(page_t *page, uint32_t order);
-#define free_page(page) __free_pages(page, 0)
-
-// Zone 查询
+// 辅助函数
 zone_t *get_zone(enum zone_type type);
 bool zone_has_memory(zone_t *zone);
+enum zone_type phys_to_zone_type(uintptr_t phys);
 
-// Zonelist 构建
-void build_zonelist(zonelist_t *zl, uint32_t gfp_flags);
-
-void init_frame_buddy(uint64_t memory_size);
-
-uintptr_t buddy_alloc_frames(size_t count);
-void buddy_free_frames(uintptr_t addr, size_t count);
+void free_frames_released(uintptr_t addr, size_t count);

src/include/mem/frame.h

@@ -11,25 +11,12 @@
 #include "metadata.h"
 #include "types.h"
 
-typedef struct {
-    void *allocator;
-    size_t total_frames;
-    size_t origin_frames;
-    size_t usable_frames;
-} FrameAllocator;
-
-extern FrameAllocator frame_allocator;
-
 uint64_t get_memory_size();
 
 void init_frame();
 uint64_t alloc_frames(size_t count);
-uint64_t alloc_frames_2M(size_t count);
-uint64_t alloc_frames_1G(size_t count);
 void free_frames(uint64_t addr, size_t count);
 void free_frame(uint64_t addr);
-void free_frames_2M(uint64_t addr);
-void free_frames_1G(uint64_t addr);
 
 uint64_t get_physical_memory_offset();
 void *phys_to_virt(uint64_t phys_addr);

src/include/mem/page_ref.h

@@ -0,0 +1,27 @@
+#pragma once
+
+#include "types.h"
+
+typedef struct page {
+    int refcount;
+    // TODO
+} page_t;
+
+extern page_t *page_maps;
+
+void page_ref_init();
+
+page_t *get_page_ref(uint64_t addr);
+
+int page_refcount_read(page_t *page);
+void page_ref(page_t *page);
+bool page_try_ref(page_t *page);
+int page_unref(page_t *page);
+bool page_try_release_last(page_t *page);
+bool page_can_free(page_t *page);
+
+bool address_ref(uint64_t addr);
+void address_unref(uint64_t addr);
+bool address_can_free(uint64_t addr);
+bool address_is_managed(uint64_t addr);
+void address_release(uint64_t addr);