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Message-ID: <157893905677.861394.8918679692049579682.stgit@toke.dk>
Date: Mon, 13 Jan 2020 19:10:56 +0100
From: Toke Høiland-Jørgensen <toke@...hat.com>
To: netdev@...r.kernel.org
Cc: bpf@...r.kernel.org, Daniel Borkmann <daniel@...earbox.net>,
Alexei Starovoitov <ast@...nel.org>,
David Miller <davem@...emloft.net>,
Jesper Dangaard Brouer <brouer@...hat.com>,
Björn Töpel <bjorn.topel@...il.com>,
John Fastabend <john.fastabend@...il.com>
Subject: [PATCH bpf-next v2 2/2] xdp: Use bulking for non-map XDP_REDIRECT and
consolidate code paths
From: Toke Høiland-Jørgensen <toke@...hat.com>
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().
Since this leaves less reason to have the non-map redirect code in a
separate function, so we get rid of the xdp_do_redirect_slow() function
entirely. This does lose us the tracepoint disambiguation, but fortunately
the xdp_redirect and xdp_redirect_map tracepoints use the same tracepoint
entry structures. This means both can contain a map index, so we can just
amend the tracepoint definitions so we always emit the xdp_redirect(_err)
tracepoints, but with the map ID only populated if a map is present. This
means we retire the xdp_redirect_map(_err) tracepoints entirely, but keep
the definitions around in case someone is still listening for them.
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@...hat.com>
---
include/linux/bpf.h | 13 +++++-
include/trace/events/xdp.h | 102 +++++++++++++++++++-------------------------
kernel/bpf/devmap.c | 31 +++++++++----
net/core/filter.c | 86 +++++++------------------------------
4 files changed, 95 insertions(+), 137 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/include/trace/events/xdp.h b/include/trace/events/xdp.h
index 72bad13d4a3c..cf568a38f852 100644
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -79,14 +79,27 @@ TRACE_EVENT(xdp_bulk_tx,
__entry->sent, __entry->drops, __entry->err)
);
+#ifndef __DEVMAP_OBJ_TYPE
+#define __DEVMAP_OBJ_TYPE
+struct _bpf_dtab_netdev {
+ struct net_device *dev;
+};
+#endif /* __DEVMAP_OBJ_TYPE */
+
+#define devmap_ifindex(tgt, map) \
+ (((map->map_type == BPF_MAP_TYPE_DEVMAP || \
+ map->map_type == BPF_MAP_TYPE_DEVMAP_HASH)) ? \
+ ((struct _bpf_dtab_netdev *)tgt)->dev->ifindex : 0)
+
+
DECLARE_EVENT_CLASS(xdp_redirect_template,
TP_PROTO(const struct net_device *dev,
const struct bpf_prog *xdp,
- int to_ifindex, int err,
- const struct bpf_map *map, u32 map_index),
+ const void *tgt, int err,
+ const struct bpf_map *map, u32 index),
- TP_ARGS(dev, xdp, to_ifindex, err, map, map_index),
+ TP_ARGS(dev, xdp, tgt, err, map, index),
TP_STRUCT__entry(
__field(int, prog_id)
@@ -103,90 +116,65 @@ DECLARE_EVENT_CLASS(xdp_redirect_template,
__entry->act = XDP_REDIRECT;
__entry->ifindex = dev->ifindex;
__entry->err = err;
- __entry->to_ifindex = to_ifindex;
+ __entry->to_ifindex = map ? devmap_ifindex(tgt, map) :
+ index;
__entry->map_id = map ? map->id : 0;
- __entry->map_index = map_index;
+ __entry->map_index = map ? index : 0;
),
- TP_printk("prog_id=%d action=%s ifindex=%d to_ifindex=%d err=%d",
+ TP_printk("prog_id=%d action=%s ifindex=%d to_ifindex=%d err=%d"
+ " map_id=%d map_index=%d",
__entry->prog_id,
__print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
__entry->ifindex, __entry->to_ifindex,
- __entry->err)
+ __entry->err, __entry->map_id, __entry->map_index)
);
DEFINE_EVENT(xdp_redirect_template, xdp_redirect,
TP_PROTO(const struct net_device *dev,
const struct bpf_prog *xdp,
- int to_ifindex, int err,
- const struct bpf_map *map, u32 map_index),
- TP_ARGS(dev, xdp, to_ifindex, err, map, map_index)
+ const void *tgt, int err,
+ const struct bpf_map *map, u32 index),
+ TP_ARGS(dev, xdp, tgt, err, map, index)
);
DEFINE_EVENT(xdp_redirect_template, xdp_redirect_err,
TP_PROTO(const struct net_device *dev,
const struct bpf_prog *xdp,
- int to_ifindex, int err,
- const struct bpf_map *map, u32 map_index),
- TP_ARGS(dev, xdp, to_ifindex, err, map, map_index)
+ const void *tgt, int err,
+ const struct bpf_map *map, u32 index),
+ TP_ARGS(dev, xdp, tgt, err, map, index)
);
#define _trace_xdp_redirect(dev, xdp, to) \
- trace_xdp_redirect(dev, xdp, to, 0, NULL, 0);
+ trace_xdp_redirect(dev, xdp, NULL, 0, NULL, to);
#define _trace_xdp_redirect_err(dev, xdp, to, err) \
- trace_xdp_redirect_err(dev, xdp, to, err, NULL, 0);
+ trace_xdp_redirect_err(dev, xdp, NULL, err, NULL, to);
+
+#define _trace_xdp_redirect_map(dev, xdp, to, map, index) \
+ trace_xdp_redirect(dev, xdp, to, 0, map, index);
-DEFINE_EVENT_PRINT(xdp_redirect_template, xdp_redirect_map,
+#define _trace_xdp_redirect_map_err(dev, xdp, to, map, index, err) \
+ trace_xdp_redirect_err(dev, xdp, to, err, map, index);
+
+/* not used anymore, but kept around so as not to break old programs */
+DEFINE_EVENT(xdp_redirect_template, xdp_redirect_map,
TP_PROTO(const struct net_device *dev,
const struct bpf_prog *xdp,
- int to_ifindex, int err,
- const struct bpf_map *map, u32 map_index),
- TP_ARGS(dev, xdp, to_ifindex, err, map, map_index),
- TP_printk("prog_id=%d action=%s ifindex=%d to_ifindex=%d err=%d"
- " map_id=%d map_index=%d",
- __entry->prog_id,
- __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
- __entry->ifindex, __entry->to_ifindex,
- __entry->err,
- __entry->map_id, __entry->map_index)
+ const void *tgt, int err,
+ const struct bpf_map *map, u32 index),
+ TP_ARGS(dev, xdp, tgt, err, map, index)
);
-DEFINE_EVENT_PRINT(xdp_redirect_template, xdp_redirect_map_err,
+DEFINE_EVENT(xdp_redirect_template, xdp_redirect_map_err,
TP_PROTO(const struct net_device *dev,
const struct bpf_prog *xdp,
- int to_ifindex, int err,
- const struct bpf_map *map, u32 map_index),
- TP_ARGS(dev, xdp, to_ifindex, err, map, map_index),
- TP_printk("prog_id=%d action=%s ifindex=%d to_ifindex=%d err=%d"
- " map_id=%d map_index=%d",
- __entry->prog_id,
- __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
- __entry->ifindex, __entry->to_ifindex,
- __entry->err,
- __entry->map_id, __entry->map_index)
+ const void *tgt, int err,
+ const struct bpf_map *map, u32 index),
+ TP_ARGS(dev, xdp, tgt, err, map, index)
);
-#ifndef __DEVMAP_OBJ_TYPE
-#define __DEVMAP_OBJ_TYPE
-struct _bpf_dtab_netdev {
- struct net_device *dev;
-};
-#endif /* __DEVMAP_OBJ_TYPE */
-
-#define devmap_ifindex(fwd, map) \
- ((map->map_type == BPF_MAP_TYPE_DEVMAP || \
- map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) ? \
- ((struct _bpf_dtab_netdev *)fwd)->dev->ifindex : 0)
-
-#define _trace_xdp_redirect_map(dev, xdp, fwd, map, idx) \
- trace_xdp_redirect_map(dev, xdp, devmap_ifindex(fwd, map), \
- 0, map, idx)
-
-#define _trace_xdp_redirect_map_err(dev, xdp, fwd, map, idx, err) \
- trace_xdp_redirect_map_err(dev, xdp, devmap_ifindex(fwd, map), \
- err, map, idx)
-
TRACE_EVENT(xdp_cpumap_kthread,
TP_PROTO(int map_id, unsigned int processed, unsigned int drops,
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 030d125c3839..db32272c4f77 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)
{
@@ -762,7 +775,7 @@ 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..f023f3a8f351 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3458,58 +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)
-{
- struct net_device *fwd;
- u32 index = ri->tgt_index;
- int err;
-
- fwd = dev_get_by_index_rcu(dev_net(dev), index);
- ri->tgt_index = 0;
- if (unlikely(!fwd)) {
- err = -EINVAL;
- goto err;
- }
-
- err = __bpf_tx_xdp(fwd, NULL, xdp, 0);
- if (unlikely(err))
- goto err;
-
- _trace_xdp_redirect(dev, xdp_prog, index);
- return 0;
-err:
- _trace_xdp_redirect_err(dev, xdp_prog, index, err);
- return err;
-}
-
static int __bpf_tx_xdp_map(struct net_device *dev_rx, void *fwd,
struct bpf_map *map, struct xdp_buff *xdp)
{
@@ -3529,7 +3477,7 @@ 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();
}
@@ -3568,10 +3516,11 @@ void bpf_clear_redirect_map(struct bpf_map *map)
}
}
-static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp,
- struct bpf_prog *xdp_prog, struct bpf_map *map,
- struct bpf_redirect_info *ri)
+int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
+ struct bpf_prog *xdp_prog)
{
+ struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
+ struct bpf_map *map = READ_ONCE(ri->map);
u32 index = ri->tgt_index;
void *fwd = ri->tgt_value;
int err;
@@ -3580,7 +3529,18 @@ static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp,
ri->tgt_value = NULL;
WRITE_ONCE(ri->map, NULL);
- err = __bpf_tx_xdp_map(dev, fwd, map, xdp);
+ if (unlikely(!map)) {
+ fwd = dev_get_by_index_rcu(dev_net(dev), index);
+ if (unlikely(!fwd)) {
+ err = -EINVAL;
+ goto err;
+ }
+
+ err = dev_xdp_enqueue(fwd, xdp, dev);
+ } else {
+ err = __bpf_tx_xdp_map(dev, fwd, map, xdp);
+ }
+
if (unlikely(err))
goto err;
@@ -3590,18 +3550,6 @@ static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp,
_trace_xdp_redirect_map_err(dev, xdp_prog, fwd, map, index, err);
return err;
}
-
-int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
- struct bpf_prog *xdp_prog)
-{
- struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
- struct bpf_map *map = READ_ONCE(ri->map);
-
- if (likely(map))
- return xdp_do_redirect_map(dev, xdp, xdp_prog, map, ri);
-
- return xdp_do_redirect_slow(dev, xdp, xdp_prog, ri);
-}
EXPORT_SYMBOL_GPL(xdp_do_redirect);
static int xdp_do_generic_redirect_map(struct net_device *dev,
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