| Message ID | 1364390288-30968-3-git-send-email-jlayton@redhat.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
On Wed, Mar 27, 2013 at 09:18:04AM -0400, Jeff Layton wrote: > void c2_init_qp_table(struct c2_dev *c2dev) > { > spin_lock_init(&c2dev->qp_table.lock); > - idr_init(&c2dev->qp_table.idr); > + idr_init_cyclic(&c2dev->qp_table.idr, 0); > } Why is this necessary? In general, why is idr_init_cyclic() necessary? Thanks.
On Wed, 27 Mar 2013 09:27:55 -0700 Tejun Heo <tj@kernel.org> wrote: > On Wed, Mar 27, 2013 at 09:18:04AM -0400, Jeff Layton wrote: > > void c2_init_qp_table(struct c2_dev *c2dev) > > { > > spin_lock_init(&c2dev->qp_table.lock); > > - idr_init(&c2dev->qp_table.idr); > > + idr_init_cyclic(&c2dev->qp_table.idr, 0); > > } > > Why is this necessary? In general, why is idr_init_cyclic() > necessary? > > Thanks. > My thinking was that you might want to initialize the "cur" value to an arbitrary value. All the current users though initialize it to the same as the "start" value passed into idr_alloc_cyclic. Starting with it at 0 should be fine in all of the existing users. I'll remove that in v2... Thanks!
diff --git a/drivers/infiniband/hw/amso1100/c2.h b/drivers/infiniband/hw/amso1100/c2.h index ba7a1208..d619d73 100644 --- a/drivers/infiniband/hw/amso1100/c2.h +++ b/drivers/infiniband/hw/amso1100/c2.h @@ -265,7 +265,6 @@ struct c2_pd_table { struct c2_qp_table { struct idr idr; spinlock_t lock; - int last; }; struct c2_element { diff --git a/drivers/infiniband/hw/amso1100/c2_qp.c b/drivers/infiniband/hw/amso1100/c2_qp.c index 0ab826b..703b33f 100644 --- a/drivers/infiniband/hw/amso1100/c2_qp.c +++ b/drivers/infiniband/hw/amso1100/c2_qp.c @@ -385,8 +385,7 @@ static int c2_alloc_qpn(struct c2_dev *c2dev, struct c2_qp *qp) idr_preload(GFP_KERNEL); spin_lock_irq(&c2dev->qp_table.lock); - ret = idr_alloc(&c2dev->qp_table.idr, qp, c2dev->qp_table.last++, 0, - GFP_NOWAIT); + ret = idr_alloc_cyclic(&c2dev->qp_table.idr, qp, 0, 0, GFP_NOWAIT); if (ret >= 0) qp->qpn = ret; @@ -1016,7 +1015,7 @@ out: void c2_init_qp_table(struct c2_dev *c2dev) { spin_lock_init(&c2dev->qp_table.lock); - idr_init(&c2dev->qp_table.idr); + idr_init_cyclic(&c2dev->qp_table.idr, 0); } void c2_cleanup_qp_table(struct c2_dev *c2dev)
(Note: compile-tested only) Signed-off-by: Jeff Layton <jlayton@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Tom Tucker <tom@opengridcomputing.com> Cc: linux-rdma@vger.kernel.org --- drivers/infiniband/hw/amso1100/c2.h | 1 - drivers/infiniband/hw/amso1100/c2_qp.c | 5 ++--- 2 files changed, 2 insertions(+), 4 deletions(-)