불연속메모리할당

커널 V. 2.6.32.65

참고 링크

페이지 테이블에 주소 변환 정보가  채워지는 원리  http://www.iamroot.org/xe/Kernel_8_ARM/54103

초보자를 위한 리눅스 커널의 메모리 관리 http://dojeun.egloos.com/317480

 

/linux/vmalloc.h

27 struct vm_struct {  28     struct vm_struct    *next;     29     void            *addr;  30     unsigned long       size;  31     unsigned long       flags;  32     struct page     **pages;  33     unsigned int        nr_pages;  34     unsigned long       phys_addr;  35     void            *caller;  36 };  54 extern void *vmalloc(unsigned long size);

/usr/src/linux-2.6.32.65/mm/vmalloc.c

 

1630  *  vmalloc  -  allocate virtually contiguous memory 1631  *  @size:      allocation size 1632  *  Allocate enough pages to cover @size from the page level 1633  *  allocator and map them into contiguous kernel virtual space. 1634  * 1635  *  For tight control over page level allocator and protection flags 1636  *  use __vmalloc() instead. 1637  */  1638 void *vmalloc(unsigned long size) 1639 {  1640     return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL, 1641                     -1, __builtin_return_address(0)); 1642 }        1572 /** 1573  *  __vmalloc_node  -  allocate virtually contiguous memory 1574  *  @size:      allocation size 1575  *  @align:     desired alignment 1576  *  @gfp_mask:  flags for the page level allocator 1577  *  @prot:      protection mask for the allocated pages 1578  *  @node:      node to use for allocation or -1 1579  *  @caller:    caller's return address 1580  * 1581  *  Allocate enough pages to cover @size from the page level 1582  *  allocator with @gfp_mask flags.  Map them into contiguous 1583  *  kernel virtual space, using a pagetable protection of @prot. 1584  */ 1585 static void *__vmalloc_node(unsigned long size, unsigned long align, 1586                 gfp_t gfp_mask, pgprot_t prot, 1587                 int node, void *caller) 1588 { 1589     struct vm_struct *area; 1590     void *addr; 1591     unsigned long real_size = size; 1592 1593     size = PAGE_ALIGN(size); 1594     if (!size || (size >> PAGE_SHIFT) > totalram_pages) 1595         return NULL; 1596 1597     area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNLIST, 1598                   VMALLOC_START, VMALLOC_END, node, 1599                   gfp_mask, caller); 1600 1601     if (!area) 1602         return NULL; 1603 1604     addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller); 1605 1606     /* 1607      * In this function, newly allocated vm_struct is not added 1608      * to vmlist at __get_vm_area_node(). so, it is added here. 1609      */ 1610     insert_vmalloc_vmlist(area); 1611 1612     /* 1613      * A ref_count = 3 is needed because the vm_struct and vmap_area 1614      * structures allocated in the __get_vm_area_node() function contain 1615      * references to the virtual address of the vmalloc'ed block. 1616      */ 1617     kmemleak_alloc(addr, real_size, 3, gfp_mask); 1618 1619     return addr; 1620 } 세그먼트 페이지 http://snowwiki.fuzewire.com/wiki/applied_sciences/computer_science/infor_science/read.html?psno=*D30ACDF27AEAFC44D3AF426EF24F0DA54E784B89