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[for-next,3/7] RDMA/rxe: Add xarray support to rxe_pool.c

Message ID 20211020220549.36145-4-rpearsonhpe@gmail.com (mailing list archive)
State Changes Requested
Delegated to: Jason Gunthorpe
Headers show
Series Replace red-black tree by xarray | expand

Commit Message

Bob Pearson Oct. 20, 2021, 10:05 p.m. UTC
Currently the rxe driver uses red-black trees to add indices and keys
to the rxe object pool. Linux xarrays provide a better way to implement
the same functionality for indices but not keys. This patch adds a
second alternative to adding indices based on cyclic allocating xarrays.
The AH pool is modified to hold either xarrays or red-black trees.
The code is tested for both options.

Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
---
 drivers/infiniband/sw/rxe/rxe_pool.c | 100 ++++++++++++++++++++++-----
 drivers/infiniband/sw/rxe/rxe_pool.h |   9 +++
 2 files changed, 92 insertions(+), 17 deletions(-)

Comments

Dennis Dalessandro Oct. 21, 2021, 11:53 a.m. UTC | #1
On 10/20/21 6:05 PM, Bob Pearson wrote:
> -		.flags		= RXE_POOL_INDEX | RXE_POOL_NO_ALLOC,
> +		//.flags		= RXE_POOL_INDEX | RXE_POOL_NO_ALLOC,
> +		.flags		= RXE_POOL_XARRAY | RXE_POOL_NO_ALLOC,

Assume you meant to remove that comment line.

-Denny
Bob Pearson Oct. 21, 2021, 5:02 p.m. UTC | #2
On 10/21/21 6:53 AM, Dennis Dalessandro wrote:
> On 10/20/21 6:05 PM, Bob Pearson wrote:
>> -		.flags		= RXE_POOL_INDEX | RXE_POOL_NO_ALLOC,
>> +		//.flags		= RXE_POOL_INDEX | RXE_POOL_NO_ALLOC,
>> +		.flags		= RXE_POOL_XARRAY | RXE_POOL_NO_ALLOC,
> 
> Assume you meant to remove that comment line.
> 
> -Denny
> 

This was an intentionally intermediate step and was a hint that you can run with either choice. In the end of the series all the old stuff goes away including the comment.
diff mbox series

Patch

diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
index 24ebd1b663c3..ba5c600fa9e8 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -25,7 +25,8 @@  static const struct rxe_type_info rxe_type_info[RXE_NUM_TYPES] = {
 		.name		= "rxe-ah",
 		.size		= sizeof(struct rxe_ah),
 		.elem_offset	= offsetof(struct rxe_ah, elem),
-		.flags		= RXE_POOL_INDEX | RXE_POOL_NO_ALLOC,
+		//.flags		= RXE_POOL_INDEX | RXE_POOL_NO_ALLOC,
+		.flags		= RXE_POOL_XARRAY | RXE_POOL_NO_ALLOC,
 		.min_index	= RXE_MIN_AH_INDEX,
 		.max_index	= RXE_MAX_AH_INDEX,
 	},
@@ -128,15 +129,20 @@  int rxe_pool_init(
 	pool->elem_size		= ALIGN(info->size, RXE_POOL_ALIGN);
 	pool->elem_offset	= info->elem_offset;
 	pool->flags		= info->flags;
-	pool->index.tree	= RB_ROOT;
-	pool->key.tree		= RB_ROOT;
 	pool->cleanup		= info->cleanup;
 
 	atomic_set(&pool->num_elem, 0);
 
 	rwlock_init(&pool->pool_lock);
 
+	if (info->flags & RXE_POOL_XARRAY) {
+		xa_init_flags(&pool->xarray.xa, XA_FLAGS_ALLOC);
+		pool->xarray.limit.max = info->max_index;
+		pool->xarray.limit.min = info->min_index;
+	}
+
 	if (info->flags & RXE_POOL_INDEX) {
+		pool->index.tree = RB_ROOT;
 		err = rxe_pool_init_index(pool, info->max_index,
 					  info->min_index);
 		if (err)
@@ -144,6 +150,7 @@  int rxe_pool_init(
 	}
 
 	if (info->flags & RXE_POOL_KEY) {
+		pool->key.tree = RB_ROOT;
 		pool->key.key_offset = info->key_offset;
 		pool->key.key_size = info->key_size;
 	}
@@ -158,7 +165,8 @@  void rxe_pool_cleanup(struct rxe_pool *pool)
 		pr_warn("%s pool destroyed with unfree'd elem\n",
 			pool->name);
 
-	kfree(pool->index.table);
+	if (pool->flags & RXE_POOL_INDEX)
+		kfree(pool->index.table);
 }
 
 /* should never fail because there are at least as many indices as
@@ -272,28 +280,35 @@  static void *__rxe_alloc_locked(struct rxe_pool *pool)
 	int err;
 
 	if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
-		goto out_cnt;
+		goto err;
 
 	obj = kzalloc(pool->elem_size, GFP_ATOMIC);
 	if (!obj)
-		goto out_cnt;
+		goto err;
 
 	elem = (struct rxe_pool_elem *)((u8 *)obj + pool->elem_offset);
 
 	elem->pool = pool;
 	elem->obj = obj;
 
+	if (pool->flags & RXE_POOL_XARRAY) {
+		err = xa_alloc_cyclic_bh(&pool->xarray.xa, &elem->index, elem,
+					 pool->xarray.limit,
+					 &pool->xarray.next, GFP_KERNEL);
+		if (err)
+			goto err;
+	}
+
 	if (pool->flags & RXE_POOL_INDEX) {
 		err = rxe_add_index(elem);
-		if (err) {
-			kfree(obj);
-			goto out_cnt;
-		}
+		if (err)
+			goto err;
 	}
 
 	return obj;
 
-out_cnt:
+err:
+	kfree(obj);
 	atomic_dec(&pool->num_elem);
 	return NULL;
 }
@@ -368,15 +383,23 @@  int __rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_elem *elem)
 
 	write_lock_bh(&pool->pool_lock);
 	if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
-		goto out_cnt;
+		goto err;
 
 	elem->pool = pool;
 	elem->obj = (u8 *)elem - pool->elem_offset;
 
+	if (pool->flags & RXE_POOL_XARRAY) {
+		err = xa_alloc_cyclic_bh(&pool->xarray.xa, &elem->index, elem,
+					 pool->xarray.limit,
+					 &pool->xarray.next, GFP_KERNEL);
+		if (err)
+			goto err;
+	}
+
 	if (pool->flags & RXE_POOL_INDEX) {
 		err = rxe_add_index(elem);
 		if (err)
-			goto out_cnt;
+			goto err;
 	}
 
 	refcount_set(&elem->refcnt, 1);
@@ -384,13 +407,13 @@  int __rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_elem *elem)
 
 	return 0;
 
-out_cnt:
+err:
 	atomic_dec(&pool->num_elem);
 	write_unlock_bh(&pool->pool_lock);
 	return -EINVAL;
 }
 
-void *rxe_pool_get_index_locked(struct rxe_pool *pool, u32 index)
+static void *__rxe_get_index_locked(struct rxe_pool *pool, u32 index)
 {
 	struct rb_node *node;
 	struct rxe_pool_elem *elem;
@@ -415,17 +438,58 @@  void *rxe_pool_get_index_locked(struct rxe_pool *pool, u32 index)
 	return obj;
 }
 
-void *rxe_pool_get_index(struct rxe_pool *pool, u32 index)
+static void *__rxe_get_index(struct rxe_pool *pool, u32 index)
+{
+	void *obj;
+
+	read_lock_bh(&pool->pool_lock);
+	obj = __rxe_get_index_locked(pool, index);
+	read_unlock_bh(&pool->pool_lock);
+
+	return obj;
+}
+
+static void *__rxe_get_xarray_locked(struct rxe_pool *pool, u32 index)
+{
+	struct rxe_pool_elem *elem;
+	void *obj = NULL;
+
+	elem = xa_load(&pool->xarray.xa, index);
+	if (elem && refcount_inc_not_zero(&elem->refcnt))
+		obj = elem->obj;
+
+	return obj;
+}
+
+static void *__rxe_get_xarray(struct rxe_pool *pool, u32 index)
 {
 	void *obj;
 
 	read_lock_bh(&pool->pool_lock);
-	obj = rxe_pool_get_index_locked(pool, index);
+	obj = __rxe_get_xarray_locked(pool, index);
 	read_unlock_bh(&pool->pool_lock);
 
 	return obj;
 }
 
+void *rxe_pool_get_index_locked(struct rxe_pool *pool, u32 index)
+{
+	if (pool->flags & RXE_POOL_XARRAY)
+		return __rxe_get_xarray_locked(pool, index);
+	if (pool->flags & RXE_POOL_INDEX)
+		return __rxe_get_index_locked(pool, index);
+	return NULL;
+}
+
+void *rxe_pool_get_index(struct rxe_pool *pool, u32 index)
+{
+	if (pool->flags & RXE_POOL_XARRAY)
+		return __rxe_get_xarray(pool, index);
+	if (pool->flags & RXE_POOL_INDEX)
+		return __rxe_get_index(pool, index);
+	return NULL;
+}
+
 void *rxe_pool_get_key_locked(struct rxe_pool *pool, void *key)
 {
 	struct rb_node *node;
@@ -519,6 +583,8 @@  static int __rxe_fini(struct rxe_pool_elem *elem)
 
 	done = refcount_dec_if_one(&elem->refcnt);
 	if (done) {
+		if (pool->flags & RXE_POOL_XARRAY)
+			xa_erase(&pool->xarray.xa, elem->index);
 		if (pool->flags & RXE_POOL_INDEX)
 			rxe_drop_index(elem);
 		if (pool->flags & RXE_POOL_KEY)
diff --git a/drivers/infiniband/sw/rxe/rxe_pool.h b/drivers/infiniband/sw/rxe/rxe_pool.h
index 3e78c275c7c5..f9c4f09cdcc9 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.h
+++ b/drivers/infiniband/sw/rxe/rxe_pool.h
@@ -8,6 +8,7 @@ 
 #define RXE_POOL_H
 
 #include <linux/refcount.h>
+#include <linux/xarray.h>
 
 #define RXE_POOL_ALIGN		(16)
 #define RXE_POOL_CACHE_FLAGS	(0)
@@ -15,6 +16,7 @@ 
 enum rxe_pool_flags {
 	RXE_POOL_INDEX		= BIT(1),
 	RXE_POOL_KEY		= BIT(2),
+	RXE_POOL_XARRAY		= BIT(3),
 	RXE_POOL_NO_ALLOC	= BIT(4),
 };
 
@@ -72,6 +74,13 @@  struct rxe_pool {
 	size_t			elem_size;
 	size_t			elem_offset;
 
+	/* only used if xarray */
+	struct {
+		struct xarray		xa;
+		struct xa_limit		limit;
+		u32			next;
+	} xarray;
+
 	/* only used if indexed */
 	struct {
 		struct rb_root		tree;