From: Maksym Planeta <mplaneta@os.inf.tu-dresden.de>
To: Moni Shoua <monis@mellanox.com>,
Doug Ledford <dledford@redhat.com>,
Jason Gunthorpe <jgg@ziepe.ca>,
linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Maksym Planeta <mplaneta@os.inf.tu-dresden.de>
Subject: [PATCH 04/10] Protect kref_put with the lock
Date: Mon, 22 Jul 2019 17:14:20 +0200 [thread overview]
Message-ID: <20190722151426.5266-5-mplaneta@os.inf.tu-dresden.de> (raw)
In-Reply-To: <20190722151426.5266-1-mplaneta@os.inf.tu-dresden.de>
Need to ensure that kref_put does not run concurrently with the loop
inside rxe_pool_get_key.
Signed-off-by: Maksym Planeta <mplaneta@os.inf.tu-dresden.de>
---
drivers/infiniband/sw/rxe/rxe_pool.c | 18 ++++++++++++++++++
drivers/infiniband/sw/rxe/rxe_pool.h | 4 +---
2 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
index efa9bab01e02..30a887cf9200 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -536,3 +536,21 @@ void *rxe_pool_get_key(struct rxe_pool *pool, void *key)
read_unlock_irqrestore(&pool->pool_lock, flags);
return node ? elem : NULL;
}
+
+static void rxe_dummy_release(struct kref *kref)
+{
+}
+
+void rxe_drop_ref(struct rxe_pool_entry *pelem)
+{
+ int res;
+ struct rxe_pool *pool = pelem->pool;
+ unsigned long flags;
+
+ write_lock_irqsave(&pool->pool_lock, flags);
+ res = kref_put(&pelem->ref_cnt, rxe_dummy_release);
+ write_unlock_irqrestore(&pool->pool_lock, flags);
+ if (res) {
+ rxe_elem_release(&pelem->ref_cnt);
+ }
+}
diff --git a/drivers/infiniband/sw/rxe/rxe_pool.h b/drivers/infiniband/sw/rxe/rxe_pool.h
index 5c6a9429f541..b90cc84c5511 100644
--- a/drivers/infiniband/sw/rxe/rxe_pool.h
+++ b/drivers/infiniband/sw/rxe/rxe_pool.h
@@ -166,8 +166,6 @@ static inline void rxe_add_ref(struct rxe_pool_entry *pelem) {
}
/* drop a reference on an object */
-static inline void rxe_drop_ref(struct rxe_pool_entry *pelem) {
- kref_put(&pelem->ref_cnt, rxe_elem_release);
-}
+void rxe_drop_ref(struct rxe_pool_entry *pelem);
#endif /* RXE_POOL_H */
--
2.20.1
next prev parent reply other threads:[~2019-07-22 15:14 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-22 15:14 [PATCH 00/10] Refactor rxe driver to remove multiple race conditions Maksym Planeta
2019-07-22 15:14 ` [PATCH 01/10] Simplify rxe_run_task interface Maksym Planeta
2019-07-22 15:14 ` [PATCH 02/10] Remove counter that does not have a meaning anymore Maksym Planeta
2019-07-22 15:14 ` [PATCH 03/10] Make pool interface more type safe Maksym Planeta
2019-07-22 15:14 ` Maksym Planeta [this message]
2019-07-22 15:25 ` [PATCH 04/10] Protect kref_put with the lock Jason Gunthorpe
2019-07-22 15:28 ` Maksym Planeta
2019-07-22 15:14 ` [PATCH 05/10] Fix reference counting for rxe tasklets Maksym Planeta
2019-07-22 15:27 ` Jason Gunthorpe
2019-07-22 15:14 ` [PATCH 06/10] Remove pd form rxe_ah Maksym Planeta
2019-07-22 15:14 ` [PATCH 07/10] Pass the return value of kref_put further Maksym Planeta
2019-07-22 15:29 ` Jason Gunthorpe
2019-07-22 15:31 ` Maksym Planeta
2019-07-22 15:14 ` [PATCH 08/10] Move responsibility of cleaning up pool elements Maksym Planeta
2019-07-22 15:14 ` [PATCH 09/10] Consolidate resetting of QP's tasks into one place Maksym Planeta
2019-07-22 15:14 ` [PATCH 10/10] Replace tasklets with workqueues Maksym Planeta
2019-07-22 15:32 ` Jason Gunthorpe
2019-07-25 14:36 ` Maksym Planeta
2019-07-25 18:50 ` Jason Gunthorpe
2019-07-30 19:20 ` Maksym Planeta
2019-10-11 10:41 ` Maksym Planeta
2019-10-22 19:04 ` Jason Gunthorpe
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