From: Ciara Loftus <ciara.loftus@intel.com>
Date: Wed, 8 Jul 2020 07:28:33 +0000
Subject: xsk: Add new statistics
Patch-mainline: v5.9-rc1
Git-commit: 8aa5a33578e9685d06020bd10d1637557423e945
References: bsc#1176447
It can be useful for the user to know the reason behind a dropped packet.
Introduce new counters which track drops on the receive path caused by:
1. rx ring being full
2. fill ring being empty
Also, on the tx path introduce a counter which tracks the number of times
we attempt pull from the tx ring when it is empty.
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200708072835.4427-2-ciara.loftus@intel.com
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
include/net/xdp_sock.h | 4 ++++
include/uapi/linux/if_xdp.h | 5 ++++-
net/xdp/xsk.c | 36 +++++++++++++++++++++++++++++++-----
net/xdp/xsk_buff_pool.c | 1 +
net/xdp/xsk_queue.h | 6 ++++++
tools/include/uapi/linux/if_xdp.h | 5 ++++-
6 files changed, 50 insertions(+), 7 deletions(-)
--- a/include/net/xdp_sock.h
+++ b/include/net/xdp_sock.h
@@ -69,7 +69,11 @@ struct xdp_sock {
spinlock_t tx_completion_lock;
/* Protects generic receive. */
spinlock_t rx_lock;
+
+ /* Statistics */
u64 rx_dropped;
+ u64 rx_queue_full;
+
struct list_head map_list;
/* Protects map_list */
spinlock_t map_list_lock;
--- a/include/uapi/linux/if_xdp.h
+++ b/include/uapi/linux/if_xdp.h
@@ -73,9 +73,12 @@ struct xdp_umem_reg {
};
struct xdp_statistics {
- __u64 rx_dropped; /* Dropped for reasons other than invalid desc */
+ __u64 rx_dropped; /* Dropped for other reasons */
__u64 rx_invalid_descs; /* Dropped due to invalid descriptor */
__u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
+ __u64 rx_ring_full; /* Dropped due to rx ring being full */
+ __u64 rx_fill_ring_empty_descs; /* Failed to retrieve item from fill ring */
+ __u64 tx_ring_empty_descs; /* Failed to retrieve item from tx ring */
};
struct xdp_options {
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -123,7 +123,7 @@ static int __xsk_rcv_zc(struct xdp_sock
addr = xp_get_handle(xskb);
err = xskq_prod_reserve_desc(xs->rx, addr, len);
if (err) {
- xs->rx_dropped++;
+ xs->rx_queue_full++;
return err;
}
@@ -274,8 +274,10 @@ bool xsk_umem_consume_tx(struct xdp_umem
rcu_read_lock();
list_for_each_entry_rcu(xs, &umem->xsk_tx_list, list) {
- if (!xskq_cons_peek_desc(xs->tx, desc, umem))
+ if (!xskq_cons_peek_desc(xs->tx, desc, umem)) {
+ xs->tx->queue_empty_descs++;
continue;
+ }
/* This is the backpressure mechanism for the Tx path.
* Reserve space in the completion queue and only proceed
@@ -387,6 +389,8 @@ static int xsk_generic_xmit(struct sock
sent_frame = true;
}
+ xs->tx->queue_empty_descs++;
+
out:
if (sent_frame)
sk->sk_write_space(sk);
@@ -812,6 +816,12 @@ static void xsk_enter_umem_offsets(struc
ring->desc = offsetof(struct xdp_umem_ring, desc);
}
+struct xdp_statistics_v1 {
+ __u64 rx_dropped;
+ __u64 rx_invalid_descs;
+ __u64 tx_invalid_descs;
+};
+
static int xsk_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
@@ -831,19 +841,35 @@ static int xsk_getsockopt(struct socket
case XDP_STATISTICS:
{
struct xdp_statistics stats;
+ bool extra_stats = true;
+ size_t stats_size;
- if (len < sizeof(stats))
+ if (len < sizeof(struct xdp_statistics_v1)) {
return -EINVAL;
+ } else if (len < sizeof(stats)) {
+ extra_stats = false;
+ stats_size = sizeof(struct xdp_statistics_v1);
+ } else {
+ stats_size = sizeof(stats);
+ }
mutex_lock(&xs->mutex);
stats.rx_dropped = xs->rx_dropped;
+ if (extra_stats) {
+ stats.rx_ring_full = xs->rx_queue_full;
+ stats.rx_fill_ring_empty_descs =
+ xs->umem ? xskq_nb_queue_empty_descs(xs->umem->fq) : 0;
+ stats.tx_ring_empty_descs = xskq_nb_queue_empty_descs(xs->tx);
+ } else {
+ stats.rx_dropped += xs->rx_queue_full;
+ }
stats.rx_invalid_descs = xskq_nb_invalid_descs(xs->rx);
stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
mutex_unlock(&xs->mutex);
- if (copy_to_user(optval, &stats, sizeof(stats)))
+ if (copy_to_user(optval, &stats, stats_size))
return -EFAULT;
- if (put_user(sizeof(stats), optlen))
+ if (put_user(stats_size, optlen))
return -EFAULT;
return 0;
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -190,6 +190,7 @@ static struct xdp_buff_xsk *__xp_alloc(s
for (;;) {
if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
+ pool->fq->queue_empty_descs++;
xp_release(xskb);
return NULL;
}
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -38,6 +38,7 @@ struct xsk_queue {
u32 cached_cons;
struct xdp_ring *ring;
u64 invalid_descs;
+ u64 queue_empty_descs;
};
/* The structure of the shared state of the rings are the same as the
@@ -354,6 +355,11 @@ static inline u64 xskq_nb_invalid_descs(
return q ? q->invalid_descs : 0;
}
+static inline u64 xskq_nb_queue_empty_descs(struct xsk_queue *q)
+{
+ return q ? q->queue_empty_descs : 0;
+}
+
struct xsk_queue *xskq_create(u32 nentries, bool umem_queue);
void xskq_destroy(struct xsk_queue *q_ops);
--- a/tools/include/uapi/linux/if_xdp.h
+++ b/tools/include/uapi/linux/if_xdp.h
@@ -73,9 +73,12 @@ struct xdp_umem_reg {
};
struct xdp_statistics {
- __u64 rx_dropped; /* Dropped for reasons other than invalid desc */
+ __u64 rx_dropped; /* Dropped for other reasons */
__u64 rx_invalid_descs; /* Dropped due to invalid descriptor */
__u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
+ __u64 rx_ring_full; /* Dropped due to rx ring being full */
+ __u64 rx_fill_ring_empty_descs; /* Failed to retrieve item from fill ring */
+ __u64 tx_ring_empty_descs; /* Failed to retrieve item from tx ring */
};
struct xdp_options {