include/linux/vmacache.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __LINUX_VMACACHE_H
   3 #define __LINUX_VMACACHE_H
   4
   5 #include <linux/sched.h>
   6 #include <linux/mm.h>
   7
   8 /*
   9  * Hash based on the page number. Provides a good hit rate for
  10  * workloads with good locality and those with random accesses as well.
  11  */
  12 #define VMACACHE_HASH(addr) ((addr >> PAGE_SHIFT) & VMACACHE_MASK)
  13
  14 static inline void vmacache_flush(struct task_struct *tsk)
  15 {
  16         memset(tsk->vmacache.vmas, 0, sizeof(tsk->vmacache.vmas));
  17 }
  18
  19 extern void vmacache_flush_all(struct mm_struct *mm);
  20 extern void vmacache_update(unsigned long addr, struct vm_area_struct *newvma);
  21 extern struct vm_area_struct *vmacache_find(struct mm_struct *mm,
  22                                                     unsigned long addr);
  23
  24 #ifndef CONFIG_MMU
  25 extern struct vm_area_struct *vmacache_find_exact(struct mm_struct *mm,
  26                                                   unsigned long start,
  27                                                   unsigned long end);
  28 #endif
  29
  30 static inline void vmacache_invalidate(struct mm_struct *mm)
  31 {
  32         mm->vmacache_seqnum++;
  33
  34         /* deal with overflows */
  35         if (unlikely(mm->vmacache_seqnum == 0))
  36                 vmacache_flush_all(mm);
  37 }
  38
  39 #endif /* __LINUX_VMACACHE_H */