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From: Bob Pearson <rpearsonhpe@gmail.com>
To: jgg@nvidia.com, zyjzyj2000@gmail.com, frank.zago@hpe.com,
	ian.ziemba@hpe.com, jhack@hpe.com, linux-rdma@vger.kernel.org
Cc: Bob Pearson <rpearsonhpe@gmail.com>
Subject: [PATCH v16 2/2] RDMA/rxe: Convert read side locking to rcu
Date: Sun, 12 Jun 2022 17:34:35 -0500	[thread overview]
Message-ID: <20220612223434.31462-3-rpearsonhpe@gmail.com> (raw)
In-Reply-To: <20220612223434.31462-1-rpearsonhpe@gmail.com>

Use rcu_read_lock() for protecting read side operations in rxe_pool.c.

Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
---
 drivers/infiniband/sw/rxe/rxe_pool.c | 27 +++++++++++----------------
 1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
index 8d8f5e409585..f50620f5a0a1 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -197,16 +197,15 @@ void *rxe_pool_get_index(struct rxe_pool *pool, u32 index)
 {
 	struct rxe_pool_elem *elem;
 	struct xarray *xa = &pool->xa;
-	unsigned long flags;
 	void *obj;
 
-	xa_lock_irqsave(xa, flags);
+	rcu_read_lock();
 	elem = xa_load(xa, index);
 	if (elem && kref_get_unless_zero(&elem->ref_cnt))
 		obj = elem->obj;
 	else
 		obj = NULL;
-	xa_unlock_irqrestore(xa, flags);
+	rcu_read_unlock();
 
 	return obj;
 }
@@ -223,16 +222,16 @@ int __rxe_cleanup(struct rxe_pool_elem *elem, bool sleepable)
 	struct rxe_pool *pool = elem->pool;
 	struct xarray *xa = &pool->xa;
 	static int timeout = RXE_POOL_TIMEOUT;
-	unsigned long flags;
 	int ret, err = 0;
 	void *xa_ret;
 
+	if (sleepable)
+		might_sleep();
+
 	/* erase xarray entry to prevent looking up
 	 * the pool elem from its index
 	 */
-	xa_lock_irqsave(xa, flags);
-	xa_ret = __xa_erase(xa, elem->index);
-	xa_unlock_irqrestore(xa, flags);
+	xa_ret = xa_erase(xa, elem->index);
 	WARN_ON(xa_err(xa_ret));
 
 	/* if this is the last call to rxe_put complete the
@@ -277,7 +276,7 @@ int __rxe_cleanup(struct rxe_pool_elem *elem, bool sleepable)
 		pool->cleanup(elem);
 
 	if (pool->type == RXE_TYPE_MR)
-		kfree(elem->obj);
+		kfree_rcu(elem->obj);
 
 	atomic_dec(&pool->num_elem);
 
@@ -296,12 +295,8 @@ int __rxe_put(struct rxe_pool_elem *elem)
 
 void __rxe_finalize(struct rxe_pool_elem *elem)
 {
-	struct xarray *xa = &elem->pool->xa;
-	unsigned long flags;
-	void *ret;
-
-	xa_lock_irqsave(xa, flags);
-	ret = __xa_store(&elem->pool->xa, elem->index, elem, GFP_KERNEL);
-	xa_unlock_irqrestore(xa, flags);
-	WARN_ON(xa_err(ret));
+	void *xa_ret;
+
+	xa_ret = xa_store(&elem->pool->xa, elem->index, elem, GFP_KERNEL);
+	WARN_ON(xa_err(xa_ret));
 }
-- 
2.34.1


  parent reply	other threads:[~2022-06-12 22:35 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-12 22:34 [PATCH for-next v16 0/2] Fix race conditions in rxe_pool Bob Pearson
2022-06-12 22:34 ` [PATCH v16 1/2] RDMA/rxe: Stop lookup of partially built objects Bob Pearson
2022-06-12 22:34 ` Bob Pearson [this message]
2022-06-30 13:58 ` [PATCH for-next v16 0/2] Fix race conditions in rxe_pool Jason Gunthorpe
2022-06-30 16:58   ` Bob Pearson

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