diff mbox series

[net-next,v10,01/14] netdev: add netdev_rx_queue_restart()

Message ID 20240530201616.1316526-2-almasrymina@google.com (mailing list archive)
State Not Applicable
Headers
Series Device Memory TCP |

Commit Message

Mina Almasry May 30, 2024, 8:16 p.m. UTC 
  Add netdev_rx_queue_restart() function to netdev_rx_queue.h

Signed-off-by: David Wei <dw@davidwei.uk>
Signed-off-by: Mina Almasry <almasrymina@google.com>

---

v9: https://lore.kernel.org/all/20240502045410.3524155-4-dw@davidwei.uk/
(submitted by David).
- fixed SPDX license identifier (Simon).
- Rebased on top of merged queue API definition, and changed
  implementation to match that.
- Replace rtnl_lock() with rtnl_is_locked() to make it useable from my
  netlink code where rtnl is already locked.

---
 include/net/netdev_rx_queue.h |  3 ++
 net/core/Makefile             |  1 +
 net/core/netdev_rx_queue.c    | 74 +++++++++++++++++++++++++++++++++++
 3 files changed, 78 insertions(+)
 create mode 100644 net/core/netdev_rx_queue.c

Comments

David Wei May 30, 2024, 11:51 p.m. UTC | #1 
On 2024-05-30 13:16, Mina Almasry wrote:
[...]
> +err_start_queue:
> +	/* Restarting the queue with old_mem should be successful as we haven't
> +	 * changed any of the queue configuration, and there is not much we can
> +	 * do to recover from a failure here.
> +	 *
> +	 * WARN if the we fail to recover the old rx queue, and at least free
> +	 * old_mem so we don't also leak that.
> +	 */
> +	if (dev->queue_mgmt_ops->ndo_queue_start(dev, old_mem, rxq_idx)) {
> +		WARN(1,
> +		     "Failed to restart old queue in error path. RX queue %d may be unhealthy.",
> +		     rxq_idx);
> +		dev->queue_mgmt_ops->ndo_queue_mem_free(dev, &old_mem);

This should be ->ndo_queue_mem_free(dev, old_mem).
Pavel Begunkov June 3, 2024, 12:52 p.m. UTC | #2 
On 5/30/24 21:16, Mina Almasry wrote:
> Add netdev_rx_queue_restart() function to netdev_rx_queue.h
> 
> Signed-off-by: David Wei <dw@davidwei.uk>
> Signed-off-by: Mina Almasry <almasrymina@google.com>
> 
> ---
...
> diff --git a/net/core/netdev_rx_queue.c b/net/core/netdev_rx_queue.c
> new file mode 100644
> index 0000000000000..b3899358e5a9c
> --- /dev/null
> +++ b/net/core/netdev_rx_queue.c
> @@ -0,0 +1,74 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include <linux/netdevice.h>
> +#include <net/netdev_queues.h>
> +#include <net/netdev_rx_queue.h>
> +
> +int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
> +{
> +	void *new_mem, *old_mem;
> +	int err;

I believe it should also do:

if (!dev->queue_mgmt_ops)
	return -EOPNOTSUPP;

> +
> +	if (!dev->queue_mgmt_ops->ndo_queue_stop ||
> +	    !dev->queue_mgmt_ops->ndo_queue_mem_free ||
> +	    !dev->queue_mgmt_ops->ndo_queue_mem_alloc ||
> +	    !dev->queue_mgmt_ops->ndo_queue_start)
> +		return -EOPNOTSUPP;
> +
> +	DEBUG_NET_WARN_ON_ONCE(!rtnl_is_locked());
diff mbox series

Patch

diff --git a/include/net/netdev_rx_queue.h b/include/net/netdev_rx_queue.h
index aa1716fb0e53c..e78ca52d67fbf 100644
--- a/include/net/netdev_rx_queue.h
+++ b/include/net/netdev_rx_queue.h
@@ -54,4 +54,7 @@  get_netdev_rx_queue_index(struct netdev_rx_queue *queue)
 	return index;
 }
 #endif
+
+int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq);
+
 #endif
diff --git a/net/core/Makefile b/net/core/Makefile
index 62be9aef25285..f82232b358a2c 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -19,6 +19,7 @@  obj-$(CONFIG_NETDEV_ADDR_LIST_TEST) += dev_addr_lists_test.o
 
 obj-y += net-sysfs.o
 obj-y += hotdata.o
+obj-y += netdev_rx_queue.o
 obj-$(CONFIG_PAGE_POOL) += page_pool.o page_pool_user.o
 obj-$(CONFIG_PROC_FS) += net-procfs.o
 obj-$(CONFIG_NET_PKTGEN) += pktgen.o
diff --git a/net/core/netdev_rx_queue.c b/net/core/netdev_rx_queue.c
new file mode 100644
index 0000000000000..b3899358e5a9c
--- /dev/null
+++ b/net/core/netdev_rx_queue.c
@@ -0,0 +1,74 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/netdevice.h>
+#include <net/netdev_queues.h>
+#include <net/netdev_rx_queue.h>
+
+int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
+{
+	void *new_mem, *old_mem;
+	int err;
+
+	if (!dev->queue_mgmt_ops->ndo_queue_stop ||
+	    !dev->queue_mgmt_ops->ndo_queue_mem_free ||
+	    !dev->queue_mgmt_ops->ndo_queue_mem_alloc ||
+	    !dev->queue_mgmt_ops->ndo_queue_start)
+		return -EOPNOTSUPP;
+
+	DEBUG_NET_WARN_ON_ONCE(!rtnl_is_locked());
+
+	new_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL);
+	if (!new_mem)
+		return -ENOMEM;
+
+	old_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL);
+	if (!old_mem) {
+		err = -ENOMEM;
+		goto err_free_new_mem;
+	}
+
+	err = dev->queue_mgmt_ops->ndo_queue_mem_alloc(dev, new_mem, rxq_idx);
+	if (err)
+		goto err_free_old_mem;
+
+	err = dev->queue_mgmt_ops->ndo_queue_stop(dev, old_mem, rxq_idx);
+	if (err)
+		goto err_free_new_queue_mem;
+
+	err = dev->queue_mgmt_ops->ndo_queue_start(dev, new_mem, rxq_idx);
+	if (err)
+		goto err_start_queue;
+
+	dev->queue_mgmt_ops->ndo_queue_mem_free(dev, old_mem);
+
+	kvfree(old_mem);
+	kvfree(new_mem);
+
+	return 0;
+
+err_start_queue:
+	/* Restarting the queue with old_mem should be successful as we haven't
+	 * changed any of the queue configuration, and there is not much we can
+	 * do to recover from a failure here.
+	 *
+	 * WARN if the we fail to recover the old rx queue, and at least free
+	 * old_mem so we don't also leak that.
+	 */
+	if (dev->queue_mgmt_ops->ndo_queue_start(dev, old_mem, rxq_idx)) {
+		WARN(1,
+		     "Failed to restart old queue in error path. RX queue %d may be unhealthy.",
+		     rxq_idx);
+		dev->queue_mgmt_ops->ndo_queue_mem_free(dev, &old_mem);
+	}
+
+err_free_new_queue_mem:
+	dev->queue_mgmt_ops->ndo_queue_mem_free(dev, new_mem);
+
+err_free_old_mem:
+	kvfree(old_mem);
+
+err_free_new_mem:
+	kvfree(new_mem);
+
+	return err;
+}