From: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Since the bulk queue used by XDP_REDIRECT now lives in struct net_device,
we can re-use the bulking for the non-map version of the bpf_redirect()
helper. This is a simple matter of having xdp_do_redirect_slow() queue the
frame on the bulk queue instead of sending it out with __bpf_tx_xdp().
Unfortunately we can't make the bpf_redirect() helper return an error if
the ifindex doesn't exit (as bpf_redirect_map() does), because we don't
have a reference to the network namespace of the ingress device at the time
the helper is called. So we have to leave it as-is and keep the device
lookup in xdp_do_redirect_slow().
With this change, the performance of the xdp_redirect sample program goes
from 5Mpps to 8.4Mpps (a 68% increase).
Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
---
include/linux/bpf.h | 13 +++++++++++--
kernel/bpf/devmap.c | 31 ++++++++++++++++++++++---------
net/core/filter.c | 30 ++----------------------------
3 files changed, 35 insertions(+), 39 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index b14e51d56a82..25c050202536 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -962,7 +962,9 @@ struct sk_buff;
struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key);
struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key);
-void __dev_map_flush(void);
+void __dev_flush(void);
+int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
+ struct net_device *dev_rx);
int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
struct net_device *dev_rx);
int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
@@ -1071,13 +1073,20 @@ static inline struct net_device *__dev_map_hash_lookup_elem(struct bpf_map *map
return NULL;
}
-static inline void __dev_map_flush(void)
+static inline void __dev_flush(void)
{
}
struct xdp_buff;
struct bpf_dtab_netdev;
+static inline
+int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
+ struct net_device *dev_rx)
+{
+ return 0;
+}
+
static inline
int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
struct net_device *dev_rx)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index bcb05cb6b728..adbb82770d02 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -81,7 +81,7 @@ struct bpf_dtab {
u32 n_buckets;
};
-static DEFINE_PER_CPU(struct list_head, dev_map_flush_list);
+static DEFINE_PER_CPU(struct list_head, dev_flush_list);
static DEFINE_SPINLOCK(dev_map_lock);
static LIST_HEAD(dev_map_list);
@@ -357,16 +357,16 @@ static int bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags)
goto out;
}
-/* __dev_map_flush is called from xdp_do_flush_map() which _must_ be signaled
+/* __dev_flush is called from xdp_do_flush_map() which _must_ be signaled
* from the driver before returning from its napi->poll() routine. The poll()
* routine is called either from busy_poll context or net_rx_action signaled
* from NET_RX_SOFTIRQ. Either way the poll routine must complete before the
* net device can be torn down. On devmap tear down we ensure the flush list
* is empty before completing to ensure all flush operations have completed.
*/
-void __dev_map_flush(void)
+void __dev_flush(void)
{
- struct list_head *flush_list = this_cpu_ptr(&dev_map_flush_list);
+ struct list_head *flush_list = this_cpu_ptr(&dev_flush_list);
struct xdp_dev_bulk_queue *bq, *tmp;
rcu_read_lock();
@@ -398,7 +398,7 @@ static int bq_enqueue(struct net_device *dev, struct xdp_frame *xdpf,
struct net_device *dev_rx)
{
- struct list_head *flush_list = this_cpu_ptr(&dev_map_flush_list);
+ struct list_head *flush_list = this_cpu_ptr(&dev_flush_list);
struct xdp_dev_bulk_queue *bq = this_cpu_ptr(dev->xdp_bulkq);
if (unlikely(bq->count == DEV_MAP_BULK_SIZE))
@@ -419,10 +419,9 @@ static int bq_enqueue(struct net_device *dev, struct xdp_frame *xdpf,
return 0;
}
-int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
- struct net_device *dev_rx)
+static inline int _xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
+ struct net_device *dev_rx)
{
- struct net_device *dev = dst->dev;
struct xdp_frame *xdpf;
int err;
@@ -440,6 +439,20 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
return bq_enqueue(dev, xdpf, dev_rx);
}
+int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
+ struct net_device *dev_rx)
+{
+ return _xdp_enqueue(dev, xdp, dev_rx);
+}
+
+int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
+ struct net_device *dev_rx)
+{
+ struct net_device *dev = dst->dev;
+
+ return _xdp_enqueue(dev, xdp, dev_rx);
+}
+
int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
struct bpf_prog *xdp_prog)
{
@@ -760,7 +773,7 @@ static int __init dev_map_init(void)
register_netdevice_notifier(&dev_map_notifier);
for_each_possible_cpu(cpu)
- INIT_LIST_HEAD(&per_cpu(dev_map_flush_list, cpu));
+ INIT_LIST_HEAD(&per_cpu(dev_flush_list, cpu));
return 0;
}
diff --git a/net/core/filter.c b/net/core/filter.c
index 42fd17c48c5f..550488162fe1 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3458,32 +3458,6 @@ static const struct bpf_func_proto bpf_xdp_adjust_meta_proto = {
.arg2_type = ARG_ANYTHING,
};
-static int __bpf_tx_xdp(struct net_device *dev,
- struct bpf_map *map,
- struct xdp_buff *xdp,
- u32 index)
-{
- struct xdp_frame *xdpf;
- int err, sent;
-
- if (!dev->netdev_ops->ndo_xdp_xmit) {
- return -EOPNOTSUPP;
- }
-
- err = xdp_ok_fwd_dev(dev, xdp->data_end - xdp->data);
- if (unlikely(err))
- return err;
-
- xdpf = convert_to_xdp_frame(xdp);
- if (unlikely(!xdpf))
- return -EOVERFLOW;
-
- sent = dev->netdev_ops->ndo_xdp_xmit(dev, 1, &xdpf, XDP_XMIT_FLUSH);
- if (sent <= 0)
- return sent;
- return 0;
-}
-
static noinline int
xdp_do_redirect_slow(struct net_device *dev, struct xdp_buff *xdp,
struct bpf_prog *xdp_prog, struct bpf_redirect_info *ri)
@@ -3499,7 +3473,7 @@ xdp_do_redirect_slow(struct net_device *dev, struct xdp_buff *xdp,
goto err;
}
- err = __bpf_tx_xdp(fwd, NULL, xdp, 0);
+ err = dev_xdp_enqueue(fwd, xdp, dev);
if (unlikely(err))
goto err;
@@ -3529,7 +3503,7 @@ static int __bpf_tx_xdp_map(struct net_device *dev_rx, void *fwd,
void xdp_do_flush_map(void)
{
- __dev_map_flush();
+ __dev_flush();
__cpu_map_flush();
__xsk_map_flush();
}
