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vdpa/mlx5: Use readers/writers semaphore instead of mutex

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Reading statistics could be done intensively and by several processes
concurrently. Reader's lock is sufficient in this case.

Change reslock from mutex to a rwsem.

Suggested-by: Si-Wei Liu <si-wei.liu@oracle.com>
Signed-off-by: Eli Cohen <elic@nvidia.com>
Message-Id: <20220518133804.1075129-7-elic@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Eli Cohen 2022-05-18 16:38:04 +03:00 committed by Michael S. Tsirkin
parent 1892a3d425
commit 759ae7f9bf
1 changed files with 19 additions and 22 deletions
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41
drivers/vdpa/mlx5/net/mlx5_vnet.c
View File

@ -155,7 +155,7 @@ struct mlx5_vdpa_net {
* since memory map might change and we need to destroy and create
* resources while driver in operational.
*/
struct mutex reslock;
struct rw_semaphore reslock;
struct mlx5_flow_table *rxft;
struct mlx5_fc *rx_counter;
struct mlx5_flow_handle *rx_rule_ucast;
@ -1695,7 +1695,7 @@ static void mlx5_cvq_kick_handler(struct work_struct *work)
ndev = to_mlx5_vdpa_ndev(mvdev);
cvq = &mvdev->cvq;
mutex_lock(&ndev->reslock);
down_write(&ndev->reslock);
if (!(mvdev->status & VIRTIO_CONFIG_S_DRIVER_OK))
goto out;
@ -1746,7 +1746,7 @@ static void mlx5_cvq_kick_handler(struct work_struct *work)
}
out:
mutex_unlock(&ndev->reslock);
up_write(&ndev->reslock);
}
static void mlx5_vdpa_kick_vq(struct vdpa_device *vdev, u16 idx)
@ -2244,7 +2244,7 @@ static int setup_driver(struct mlx5_vdpa_dev *mvdev)
struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
int err;
WARN_ON(!mutex_is_locked(&ndev->reslock));
WARN_ON(!rwsem_is_locked(&ndev->reslock));
if (ndev->setup) {
mlx5_vdpa_warn(mvdev, "setup driver called for already setup driver\n");
@ -2292,7 +2292,7 @@ out:
static void teardown_driver(struct mlx5_vdpa_net *ndev)
{
WARN_ON(!mutex_is_locked(&ndev->reslock));
WARN_ON(!rwsem_is_locked(&ndev->reslock));
if (!ndev->setup)
return;
@ -2322,7 +2322,7 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
print_status(mvdev, status, true);
mutex_lock(&ndev->reslock);
down_write(&ndev->reslock);
if ((status ^ ndev->mvdev.status) & VIRTIO_CONFIG_S_DRIVER_OK) {
if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
@ -2338,14 +2338,14 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
}
ndev->mvdev.status = status;
mutex_unlock(&ndev->reslock);
up_write(&ndev->reslock);
return;
err_setup:
mlx5_vdpa_destroy_mr(&ndev->mvdev);
ndev->mvdev.status |= VIRTIO_CONFIG_S_FAILED;
err_clear:
mutex_unlock(&ndev->reslock);
up_write(&ndev->reslock);
}
static int mlx5_vdpa_reset(struct vdpa_device *vdev)
@ -2356,7 +2356,7 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev)
print_status(mvdev, 0, true);
mlx5_vdpa_info(mvdev, "performing device reset\n");
mutex_lock(&ndev->reslock);
down_write(&ndev->reslock);
teardown_driver(ndev);
clear_vqs_ready(ndev);
mlx5_vdpa_destroy_mr(&ndev->mvdev);
@ -2371,7 +2371,7 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev)
if (mlx5_vdpa_create_mr(mvdev, NULL))
mlx5_vdpa_warn(mvdev, "create MR failed\n");
}
mutex_unlock(&ndev->reslock);
up_write(&ndev->reslock);
return 0;
}
@ -2411,7 +2411,7 @@ static int mlx5_vdpa_set_map(struct vdpa_device *vdev, struct vhost_iotlb *iotlb
bool change_map;
int err;
mutex_lock(&ndev->reslock);
down_write(&ndev->reslock);
err = mlx5_vdpa_handle_set_map(mvdev, iotlb, &change_map);
if (err) {
@ -2423,7 +2423,7 @@ static int mlx5_vdpa_set_map(struct vdpa_device *vdev, struct vhost_iotlb *iotlb
err = mlx5_vdpa_change_map(mvdev, iotlb);
err:
mutex_unlock(&ndev->reslock);
up_write(&ndev->reslock);
return err;
}
@ -2442,7 +2442,6 @@ static void mlx5_vdpa_free(struct vdpa_device *vdev)
mlx5_mpfs_del_mac(pfmdev, ndev->config.mac);
}
mlx5_vdpa_free_resources(&ndev->mvdev);
mutex_destroy(&ndev->reslock);
kfree(ndev->event_cbs);
kfree(ndev->vqs);
}
@ -2527,7 +2526,7 @@ static int mlx5_vdpa_get_vendor_vq_stats(struct vdpa_device *vdev, u16 idx,
u64 completed_desc;
int err = 0;
mutex_lock(&ndev->reslock);
down_read(&ndev->reslock);
if (!is_index_valid(mvdev, idx)) {
NL_SET_ERR_MSG_MOD(extack, "virtqueue index is not valid");
err = -EINVAL;
@ -2566,7 +2565,7 @@ out:
err = 0;
out_err:
mutex_unlock(&ndev->reslock);
up_read(&ndev->reslock);
return err;
}
@ -2835,18 +2834,18 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
}
init_mvqs(ndev);
mutex_init(&ndev->reslock);
init_rwsem(&ndev->reslock);
config = &ndev->config;
if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU)) {
err = config_func_mtu(mdev, add_config->net.mtu);
if (err)
goto err_mtu;
goto err_alloc;
}
err = query_mtu(mdev, &mtu);
if (err)
goto err_mtu;
goto err_alloc;
ndev->config.mtu = cpu_to_mlx5vdpa16(mvdev, mtu);
@ -2860,14 +2859,14 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
} else {
err = mlx5_query_nic_vport_mac_address(mdev, 0, 0, config->mac);
if (err)
goto err_mtu;
goto err_alloc;
}
if (!is_zero_ether_addr(config->mac)) {
pfmdev = pci_get_drvdata(pci_physfn(mdev->pdev));
err = mlx5_mpfs_add_mac(pfmdev, config->mac);
if (err)
goto err_mtu;
goto err_alloc;
ndev->mvdev.mlx_features |= BIT_ULL(VIRTIO_NET_F_MAC);
}
@ -2917,8 +2916,6 @@ err_res:
err_mpfs:
if (!is_zero_ether_addr(config->mac))
mlx5_mpfs_del_mac(pfmdev, config->mac);
err_mtu:
mutex_destroy(&ndev->reslock);
err_alloc:
put_device(&mvdev->vdev.dev);
return err;