标签：style blog io color ar for sp div on
page : logic virtual page
page frame : physical memory page ,
struct page
{
unsigned long flags :
atomic_t count ;
struct list_head list;
struct address_space *mapping;
unsigned long index;
union
{
struct pte_chain *chain;
pte_addr_t direct;
}
unsigned long private;
#if defined WANT_PAGE_VIRTUAL
void *virtual;
#endif
}
here we have the definition of memory zone :
struct zone { spinlock_t lock; //for read and write synchronization unsigned long free_pages; //the left blank pages unsigned long pages_min , pages_low , pages_high ; //threshold , for kernel judging current usage situation spinlock_t lru_lock; struct list_head active_list; struct list_head inactive_list; atomic_t refill_counter; unsigned long nr_active , nr_inactive; int all_unreclaimable; unsigned long pages_scanned; int temp_priority; int prev_priority; struct free_area free_area[MAX_ORDER]; wait_queue_head_t *wait_table; unsigned long wait_table_size; unsigned long wait_table_bits; }; struct kmem_cache_s { struct kmem_list3 lists; //partial , complete , empty list unsigned int objsize; //object size in the cache unsigned int flag; unsigned int num; //num of object unsigned int gfporder; //order of cache in page unsigned int gfpflags; //flag of cache in page size_t color; unsigned int color_off; unsigned int color_next; kmem_cache_t *slabp_cache; // unsigned int dflags; void (*ctor)(void *,kmem_cache_t *,unsigned long); void (*dtor)(void *,kmem_cache_t *,unsigned long); const char *name; //name of object struct list_head next; }; struct mm_struct { struct vm_area_struct *mmap; struct rb_root mm_rb; struct vm_area_struct *mmap_cache; unsigned long free_area_cache; pgd_t *pgd; atomic_t mm_users; atomic_t mm_count; int map_count; struct rw_semaphore mmap_sem; spinloct_t page_table_lock; struct list_head mmlist; unsigned long start_code , end_code , start_data , end_data; unsigned long start_brk , brk , start_stack; //we call heap as brick, namely brk in kernel unsigned long arg_start , arg_end , env_start , env_end; unsigned long rss , total_vm , locked_vm; unsigned long def_flags; cpumask_t cpu_vm_mask; unsigned long swap_address; };
struct vm_area_struct { struct mm_struct *vm_mm; unsigned long vm_start, vm_end; struct vm_area_struct *vm_next; unsigned long vm_flags; struct rb_node vm_rb; struct vm_operations_struct *vm_ops; };
when application call for malloc() to expand current heap space , kernel will use sys_brk() to move brk to new place .
3 level paging mechanical here:
PGD : page global diretory
PMD : page middle directory
PTE : page table entry
标签：style blog io color ar for sp div on
原文地址：http://www.cnblogs.com/dragen/p/4055207.html
