mm/vmacache, sched/headers: Introduce 'struct vmacache' and move it from <linux/sched.h> to <linux/mm_types>

The <linux/sched.h> header includes various vmacache related defines,
which are arguably misplaced.

Move them to mm_types.h and minimize the sched.h impact by putting
all task vmacache state into a new 'struct vmacache' structure.

No change in functionality.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/mm/vmacache.c b/mm/vmacache.c
index 035fdeb..7c233f8 100644
--- a/mm/vmacache.c
+++ b/mm/vmacache.c
@@ -60,7 +60,7 @@ static inline bool vmacache_valid_mm(struct mm_struct *mm)
 void vmacache_update(unsigned long addr, struct vm_area_struct *newvma)
 {
 	if (vmacache_valid_mm(newvma->vm_mm))
-		current->vmacache[VMACACHE_HASH(addr)] = newvma;
+		current->vmacache.vmas[VMACACHE_HASH(addr)] = newvma;
 }
 
 static bool vmacache_valid(struct mm_struct *mm)
@@ -71,12 +71,12 @@ static bool vmacache_valid(struct mm_struct *mm)
 		return false;
 
 	curr = current;
-	if (mm->vmacache_seqnum != curr->vmacache_seqnum) {
+	if (mm->vmacache_seqnum != curr->vmacache.seqnum) {
 		/*
 		 * First attempt will always be invalid, initialize
 		 * the new cache for this task here.
 		 */
-		curr->vmacache_seqnum = mm->vmacache_seqnum;
+		curr->vmacache.seqnum = mm->vmacache_seqnum;
 		vmacache_flush(curr);
 		return false;
 	}
@@ -93,7 +93,7 @@ struct vm_area_struct *vmacache_find(struct mm_struct *mm, unsigned long addr)
 		return NULL;
 
 	for (i = 0; i < VMACACHE_SIZE; i++) {
-		struct vm_area_struct *vma = current->vmacache[i];
+		struct vm_area_struct *vma = current->vmacache.vmas[i];
 
 		if (!vma)
 			continue;
@@ -121,7 +121,7 @@ struct vm_area_struct *vmacache_find_exact(struct mm_struct *mm,
 		return NULL;
 
 	for (i = 0; i < VMACACHE_SIZE; i++) {
-		struct vm_area_struct *vma = current->vmacache[i];
+		struct vm_area_struct *vma = current->vmacache.vmas[i];
 
 		if (vma && vma->vm_start == start && vma->vm_end == end) {
 			count_vm_vmacache_event(VMACACHE_FIND_HITS);