include/linux/vmacache.h

   1 #ifndef __LINUX_VMACACHE_H
   2 #define __LINUX_VMACACHE_H
   3
   4 #include <linux/sched.h>
   5 #include <linux/mm.h>
   6
   7 /*
   8  * Hash based on the page number. Provides a good hit rate for
   9  * workloads with good locality and those with random accesses as well.
  10  */
  11 #define VMACACHE_HASH(addr) ((addr >> PAGE_SHIFT) & VMACACHE_MASK)
  12
  13 static inline void vmacache_flush(struct task_struct *tsk)
  14 {
  15         memset(tsk->vmacache, 0, sizeof(tsk->vmacache));
  16 }
  17
  18 extern void vmacache_flush_all(struct mm_struct *mm);
  19 extern void vmacache_update(unsigned long addr, struct vm_area_struct *newvma);
  20 extern struct vm_area_struct *vmacache_find(struct mm_struct *mm,
  21                                                     unsigned long addr);
  22
  23 #ifndef CONFIG_MMU
  24 extern struct vm_area_struct *vmacache_find_exact(struct mm_struct *mm,
  25                                                   unsigned long start,
  26                                                   unsigned long end);
  27 #endif
  28
  29 static inline void vmacache_invalidate(struct mm_struct *mm)
  30 {
  31         mm->vmacache_seqnum++;
  32
  33         /* deal with overflows */
  34         if (unlikely(mm->vmacache_seqnum == 0))
  35                 vmacache_flush_all(mm);
  36 }
  37
  38 #endif /* __LINUX_VMACACHE_H */