On 04-Feb-19 23:17, Jason Gunthorpe wrote:
> From: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
>
> This gives each client a unique ID and will let us move client_data to use
> xarray, and revise the locking scheme.
>
> clients have to be add/removed in strict FIFO/LIFO order as they
> interdepend. To support this the client_ids are assigned to increase in
> FIFO order. The existing linked list is kept to support reverse iteration
> until xarray can get a reverse iteration API.
>
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
> Reviewed-by: Parav Pandit <parav@xxxxxxxxxxxx>
> ---
> drivers/infiniband/core/device.c | 50 ++++++++++++++++++++++++++++----
> include/rdma/ib_verbs.h | 3 +-
> 2 files changed, 47 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
> index 300a36beaa300c..f485e77223d429 100644
> --- a/drivers/infiniband/core/device.c
> +++ b/drivers/infiniband/core/device.c
> @@ -65,15 +65,17 @@ struct workqueue_struct *ib_comp_unbound_wq;
> struct workqueue_struct *ib_wq;
> EXPORT_SYMBOL_GPL(ib_wq);
>
> -/* The device_list and client_list contain devices and clients after their
> +/* The device_list and clients contain devices and clients after their
> * registration has completed, and the devices and clients are removed
> * during unregistration. */
> static LIST_HEAD(device_list);
> static LIST_HEAD(client_list);
> +#define CLIENT_REGISTERED XA_MARK_1
> +static DEFINE_XARRAY_FLAGS(clients, XA_FLAGS_ALLOC);
>
> /*
> * device_mutex and lists_rwsem protect access to both device_list and
> - * client_list. device_mutex protects writer access by device and client
> + * clients. device_mutex protects writer access by device and client
> * registration / de-registration. lists_rwsem protects reader access to
> * these lists. Iterators of these lists must lock it for read, while updates
> * to the lists must be done with a write lock. A special case is when the
> @@ -563,6 +565,7 @@ int ib_register_device(struct ib_device *device, const char *name)
> {
> int ret;
> struct ib_client *client;
> + unsigned long index;
>
> setup_dma_device(device);
>
> @@ -607,7 +610,7 @@ int ib_register_device(struct ib_device *device, const char *name)
>
> refcount_set(&device->refcount, 1);
>
> - list_for_each_entry(client, &client_list, list)
> + xa_for_each_marked (&clients, index, client, CLIENT_REGISTERED)
nit: extra space after xa_for_each_marked.
