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authorMichel Lespinasse <walken@google.com>2019-09-26 01:46:07 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-26 02:51:39 +0200
commit315cc066b8ae8349a27887ad7a34e1916e9797fe (patch)
tree3c7dba850cee3ec6991228ae425db0de78fbb252 /mm/mmap.c
parentaugmented rbtree: add comments for RB_DECLARE_CALLBACKS macro (diff)
downloadlinux-315cc066b8ae8349a27887ad7a34e1916e9797fe.tar.xz
linux-315cc066b8ae8349a27887ad7a34e1916e9797fe.zip
augmented rbtree: add new RB_DECLARE_CALLBACKS_MAX macro
Add RB_DECLARE_CALLBACKS_MAX, which generates augmented rbtree callbacks for the case where the augmented value is a scalar whose definition follows a max(f(node)) pattern. This actually covers all present uses of RB_DECLARE_CALLBACKS, and saves some (source) code duplication in the various RBCOMPUTE function definitions. [walken@google.com: fix mm/vmalloc.c] Link: http://lkml.kernel.org/r/CANN689FXgK13wDYNh1zKxdipeTuALG4eKvKpsdZqKFJ-rvtGiQ@mail.gmail.com [walken@google.com: re-add check to check_augmented()] Link: http://lkml.kernel.org/r/20190727022027.GA86863@google.com Link: http://lkml.kernel.org/r/20190703040156.56953-3-walken@google.com Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David Howells <dhowells@redhat.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
-rw-r--r--mm/mmap.c29
1 files changed, 18 insertions, 11 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index f1e8c7f93e04..14b7da317ec0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -289,9 +289,9 @@ out:
return retval;
}
-static long vma_compute_subtree_gap(struct vm_area_struct *vma)
+static inline unsigned long vma_compute_gap(struct vm_area_struct *vma)
{
- unsigned long max, prev_end, subtree_gap;
+ unsigned long gap, prev_end;
/*
* Note: in the rare case of a VM_GROWSDOWN above a VM_GROWSUP, we
@@ -299,14 +299,21 @@ static long vma_compute_subtree_gap(struct vm_area_struct *vma)
* an unmapped area; whereas when expanding we only require one.
* That's a little inconsistent, but keeps the code here simpler.
*/
- max = vm_start_gap(vma);
+ gap = vm_start_gap(vma);
if (vma->vm_prev) {
prev_end = vm_end_gap(vma->vm_prev);
- if (max > prev_end)
- max -= prev_end;
+ if (gap > prev_end)
+ gap -= prev_end;
else
- max = 0;
+ gap = 0;
}
+ return gap;
+}
+
+#ifdef CONFIG_DEBUG_VM_RB
+static unsigned long vma_compute_subtree_gap(struct vm_area_struct *vma)
+{
+ unsigned long max = vma_compute_gap(vma), subtree_gap;
if (vma->vm_rb.rb_left) {
subtree_gap = rb_entry(vma->vm_rb.rb_left,
struct vm_area_struct, vm_rb)->rb_subtree_gap;
@@ -322,7 +329,6 @@ static long vma_compute_subtree_gap(struct vm_area_struct *vma)
return max;
}
-#ifdef CONFIG_DEBUG_VM_RB
static int browse_rb(struct mm_struct *mm)
{
struct rb_root *root = &mm->mm_rb;
@@ -428,8 +434,9 @@ static void validate_mm(struct mm_struct *mm)
#define validate_mm(mm) do { } while (0)
#endif
-RB_DECLARE_CALLBACKS(static, vma_gap_callbacks, struct vm_area_struct, vm_rb,
- unsigned long, rb_subtree_gap, vma_compute_subtree_gap)
+RB_DECLARE_CALLBACKS_MAX(static, vma_gap_callbacks,
+ struct vm_area_struct, vm_rb,
+ unsigned long, rb_subtree_gap, vma_compute_gap)
/*
* Update augmented rbtree rb_subtree_gap values after vma->vm_start or
@@ -439,8 +446,8 @@ RB_DECLARE_CALLBACKS(static, vma_gap_callbacks, struct vm_area_struct, vm_rb,
static void vma_gap_update(struct vm_area_struct *vma)
{
/*
- * As it turns out, RB_DECLARE_CALLBACKS() already created a callback
- * function that does exactly what we want.
+ * As it turns out, RB_DECLARE_CALLBACKS_MAX() already created
+ * a callback function that does exactly what we want.
*/
vma_gap_callbacks_propagate(&vma->vm_rb, NULL);
}