diff options
| author | Andreea-Cristina Bernat <bernat.ada@gmail.com> | 2015-01-16 10:19:53 -0500 |
|---|---|---|
| committer | Roland Dreier <roland@purestorage.com> | 2015-02-17 10:26:19 -0800 |
| commit | 03c885913f914d17124432dd50caf2923a80847c (patch) | |
| tree | 3db8e8bb201844385275b6a4e58acc9458a29552 /drivers/infiniband | |
| parent | 0e6bbba56c54f6305f24f0ad8991f5b5d03ae2b5 (diff) | |
IB/qib: Replace rcu_assign_pointer() with RCU_INIT_POINTER() in qib_qp.c
According to RCU_INIT_POINTER()'s block comment 3.a, it can be used if
"1. This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.
"3. The referenced data structure has already been exposed to readers either
at compile time or via rcu_assign_pointer() -and-
a. You have not made -any- reader-visible changes to this structure since
then".
These cases fulfill the conditions above because between the
rcu_dereference_protected() call and the rcu_assign_pointer() call
there is no update of that value. Therefore, this patch makes the
replacement.
The following Coccinelle semantic patch was used:
@@
@@
- rcu_assign_pointer
+ RCU_INIT_POINTER
(...,
(
rtnl_dereference(...)
|
rcu_dereference_protected(...)
) )
[consolidated from http://marc.info/?l=linux-rdma&m=140836578119485&w=2 and
http://marc.info/?l=linux-rdma&m=140906361403047&w=2]
Tested-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Diffstat (limited to 'drivers/infiniband')
| -rw-r--r-- | drivers/infiniband/hw/qib/qib_qp.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/infiniband/hw/qib/qib_qp.c b/drivers/infiniband/hw/qib/qib_qp.c index 6ddc0264aad2..4fa88ba2963e 100644 --- a/drivers/infiniband/hw/qib/qib_qp.c +++ b/drivers/infiniband/hw/qib/qib_qp.c @@ -255,10 +255,10 @@ static void remove_qp(struct qib_ibdev *dev, struct qib_qp *qp) if (rcu_dereference_protected(ibp->qp0, lockdep_is_held(&dev->qpt_lock)) == qp) { - rcu_assign_pointer(ibp->qp0, NULL); + RCU_INIT_POINTER(ibp->qp0, NULL); } else if (rcu_dereference_protected(ibp->qp1, lockdep_is_held(&dev->qpt_lock)) == qp) { - rcu_assign_pointer(ibp->qp1, NULL); + RCU_INIT_POINTER(ibp->qp1, NULL); } else { struct qib_qp *q; struct qib_qp __rcu **qpp; @@ -269,7 +269,7 @@ static void remove_qp(struct qib_ibdev *dev, struct qib_qp *qp) lockdep_is_held(&dev->qpt_lock))) != NULL; qpp = &q->next) if (q == qp) { - rcu_assign_pointer(*qpp, + RCU_INIT_POINTER(*qpp, rcu_dereference_protected(qp->next, lockdep_is_held(&dev->qpt_lock))); removed = 1; @@ -315,7 +315,7 @@ unsigned qib_free_all_qps(struct qib_devdata *dd) for (n = 0; n < dev->qp_table_size; n++) { qp = rcu_dereference_protected(dev->qp_table[n], lockdep_is_held(&dev->qpt_lock)); - rcu_assign_pointer(dev->qp_table[n], NULL); + RCU_INIT_POINTER(dev->qp_table[n], NULL); for (; qp; qp = rcu_dereference_protected(qp->next, lockdep_is_held(&dev->qpt_lock))) |