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authorTejun Heo <tj@kernel.org>2013-02-27 17:05:05 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-27 19:10:20 -0800
commit1d9b2e1e663719d406e3a770979a19ba4233bba0 (patch)
tree359bf3e2dce77fda66d42296992e705f0b305ea1
parente8c8d1bc063bc88cfa1356266027b5075d3a82d7 (diff)
idr: remove length restriction from idr_layer->bitmap
Currently, idr->bitmap is declared as an unsigned long which restricts the number of bits an idr_layer can contain. All bitops can handle arbitrary positive integer bit number and there's no reason for this restriction. Declare idr_layer->bitmap using DECLARE_BITMAP() instead of a single unsigned long. * idr_layer->bitmap is now an array. '&' dropped from params to bitops. * Replaced "== IDR_FULL" tests with bitmap_full() and removed IDR_FULL. * Replaced find_next_bit() on ~bitmap with find_next_zero_bit(). * Replaced "bitmap = 0" with bitmap_clear(). This patch doesn't (or at least shouldn't) introduce any behavior changes. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/idr.h12
-rw-r--r--lib/idr.c34
2 files changed, 18 insertions, 28 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h
index 99b0ce533f0e..63aa542da49b 100644
--- a/include/linux/idr.h
+++ b/include/linux/idr.h
@@ -19,18 +19,8 @@
#if BITS_PER_LONG == 32
# define IDR_BITS 5
-# define IDR_FULL 0xfffffffful
-/* We can only use two of the bits in the top level because there is
- only one possible bit in the top level (5 bits * 7 levels = 35
- bits, but you only use 31 bits in the id). */
-# define TOP_LEVEL_FULL (IDR_FULL >> 30)
#elif BITS_PER_LONG == 64
# define IDR_BITS 6
-# define IDR_FULL 0xfffffffffffffffful
-/* We can only use two of the bits in the top level because there is
- only one possible bit in the top level (6 bits * 6 levels = 36
- bits, but you only use 31 bits in the id). */
-# define TOP_LEVEL_FULL (IDR_FULL >> 62)
#else
# error "BITS_PER_LONG is not 32 or 64"
#endif
@@ -39,7 +29,7 @@
#define IDR_MASK ((1 << IDR_BITS)-1)
struct idr_layer {
- unsigned long bitmap; /* A zero bit means "space here" */
+ DECLARE_BITMAP(bitmap, IDR_SIZE); /* A zero bit means "space here" */
struct idr_layer __rcu *ary[1<<IDR_BITS];
int count; /* When zero, we can release it */
int layer; /* distance from leaf */
diff --git a/lib/idr.c b/lib/idr.c
index e2b799989ab0..d66e75bfc1a0 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -157,18 +157,18 @@ static void idr_mark_full(struct idr_layer **pa, int id)
struct idr_layer *p = pa[0];
int l = 0;
- __set_bit(id & IDR_MASK, &p->bitmap);
+ __set_bit(id & IDR_MASK, p->bitmap);
/*
* If this layer is full mark the bit in the layer above to
* show that this part of the radix tree is full. This may
* complete the layer above and require walking up the radix
* tree.
*/
- while (p->bitmap == IDR_FULL) {
+ while (bitmap_full(p->bitmap, IDR_SIZE)) {
if (!(p = pa[++l]))
break;
id = id >> IDR_BITS;
- __set_bit((id & IDR_MASK), &p->bitmap);
+ __set_bit((id & IDR_MASK), p->bitmap);
}
}
@@ -221,7 +221,6 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa,
int n, m, sh;
struct idr_layer *p, *new;
int l, id, oid;
- unsigned long bm;
id = *starting_id;
restart:
@@ -233,8 +232,7 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa,
* We run around this while until we reach the leaf node...
*/
n = (id >> (IDR_BITS*l)) & IDR_MASK;
- bm = ~p->bitmap;
- m = find_next_bit(&bm, IDR_SIZE, n);
+ m = find_next_zero_bit(p->bitmap, IDR_SIZE, n);
if (m == IDR_SIZE) {
/* no space available go back to previous layer. */
l++;
@@ -326,7 +324,8 @@ build_up:
for (new = p; p && p != idp->top; new = p) {
p = p->ary[0];
new->ary[0] = NULL;
- new->bitmap = new->count = 0;
+ new->count = 0;
+ bitmap_clear(new->bitmap, 0, IDR_SIZE);
__move_to_free_list(idp, new);
}
spin_unlock_irqrestore(&idp->lock, flags);
@@ -335,8 +334,8 @@ build_up:
new->ary[0] = p;
new->count = 1;
new->layer = layers-1;
- if (p->bitmap == IDR_FULL)
- __set_bit(0, &new->bitmap);
+ if (bitmap_full(p->bitmap, IDR_SIZE))
+ __set_bit(0, new->bitmap);
p = new;
}
rcu_assign_pointer(idp->top, p);
@@ -517,14 +516,14 @@ static void sub_remove(struct idr *idp, int shift, int id)
while ((shift > 0) && p) {
n = (id >> shift) & IDR_MASK;
- __clear_bit(n, &p->bitmap);
+ __clear_bit(n, p->bitmap);
*++paa = &p->ary[n];
p = p->ary[n];
shift -= IDR_BITS;
}
n = id & IDR_MASK;
- if (likely(p != NULL && test_bit(n, &p->bitmap))){
- __clear_bit(n, &p->bitmap);
+ if (likely(p != NULL && test_bit(n, p->bitmap))) {
+ __clear_bit(n, p->bitmap);
rcu_assign_pointer(p->ary[n], NULL);
to_free = NULL;
while(*paa && ! --((**paa)->count)){
@@ -567,7 +566,8 @@ void idr_remove(struct idr *idp, int id)
p = idp->top->ary[0];
rcu_assign_pointer(idp->top, p);
--idp->layers;
- to_free->bitmap = to_free->count = 0;
+ to_free->count = 0;
+ bitmap_clear(to_free->bitmap, 0, IDR_SIZE);
free_layer(to_free);
}
while (idp->id_free_cnt >= MAX_IDR_FREE) {
@@ -827,7 +827,7 @@ void *idr_replace(struct idr *idp, void *ptr, int id)
}
n = id & IDR_MASK;
- if (unlikely(p == NULL || !test_bit(n, &p->bitmap)))
+ if (unlikely(p == NULL || !test_bit(n, p->bitmap)))
return ERR_PTR(-ENOENT);
old_p = p->ary[n];
@@ -1024,7 +1024,7 @@ void ida_remove(struct ida *ida, int id)
/* clear full bits while looking up the leaf idr_layer */
while ((shift > 0) && p) {
n = (idr_id >> shift) & IDR_MASK;
- __clear_bit(n, &p->bitmap);
+ __clear_bit(n, p->bitmap);
p = p->ary[n];
shift -= IDR_BITS;
}
@@ -1033,7 +1033,7 @@ void ida_remove(struct ida *ida, int id)
goto err;
n = idr_id & IDR_MASK;
- __clear_bit(n, &p->bitmap);
+ __clear_bit(n, p->bitmap);
bitmap = (void *)p->ary[n];
if (!test_bit(offset, bitmap->bitmap))
@@ -1042,7 +1042,7 @@ void ida_remove(struct ida *ida, int id)
/* update bitmap and remove it if empty */
__clear_bit(offset, bitmap->bitmap);
if (--bitmap->nr_busy == 0) {
- __set_bit(n, &p->bitmap); /* to please idr_remove() */
+ __set_bit(n, p->bitmap); /* to please idr_remove() */
idr_remove(&ida->idr, idr_id);
free_bitmap(ida, bitmap);
}