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xdp: Make devmap flush_list common for all map instances

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The devmap flush list is used to track entries that need to flushed
from via the xdp_do_flush_map() function. This list used to be
per-map, but there is really no reason for that. Instead make the
flush list global for all devmaps, which simplifies __dev_map_flush()
and dev_map_init_map().

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191219061006.21980-6-bjorn.topel@gmail.com
This commit is contained in:
Björn Töpel 2019-12-19 07:10:03 +01:00 committed by Alexei Starovoitov
parent e312b9e706
commit 96360004b8
3 changed files with 16 additions and 25 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

4
include/linux/bpf.h
View file

@ -959,7 +959,7 @@ struct sk_buff;
struct bpf_dtab_netdev *__dev_map_lookup_elem(struct bpf_map *map, u32 key); 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); struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key);
void __dev_map_flush(struct bpf_map *map); void __dev_map_flush(void);
int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp, int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
struct net_device *dev_rx); struct net_device *dev_rx);
int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
@ -1068,7 +1068,7 @@ static inline struct net_device *__dev_map_hash_lookup_elem(struct bpf_map *map
return NULL; return NULL;
} }
static inline void __dev_map_flush(struct bpf_map *map) static inline void __dev_map_flush(void)
{ {
} }

35
kernel/bpf/devmap.c
View file

@ -75,7 +75,6 @@ struct bpf_dtab_netdev {
struct bpf_dtab { struct bpf_dtab {
struct bpf_map map; struct bpf_map map;
struct bpf_dtab_netdev **netdev_map; /* DEVMAP type only */ struct bpf_dtab_netdev **netdev_map; /* DEVMAP type only */
struct list_head __percpu *flush_list;
struct list_head list; struct list_head list;
/* these are only used for DEVMAP_HASH type maps */ /* these are only used for DEVMAP_HASH type maps */
@ -85,6 +84,7 @@ struct bpf_dtab {
u32 n_buckets; u32 n_buckets;
}; };
static DEFINE_PER_CPU(struct list_head, dev_map_flush_list);
static DEFINE_SPINLOCK(dev_map_lock); static DEFINE_SPINLOCK(dev_map_lock);
static LIST_HEAD(dev_map_list); static LIST_HEAD(dev_map_list);
@ -109,8 +109,8 @@ static inline struct hlist_head *dev_map_index_hash(struct bpf_dtab *dtab,
static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
{ {
int err, cpu; u64 cost = 0;
u64 cost; int err;
/* check sanity of attributes */ /* check sanity of attributes */
if (attr->max_entries == 0 || attr->key_size != 4 || if (attr->max_entries == 0 || attr->key_size != 4 ||
@ -125,9 +125,6 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
bpf_map_init_from_attr(&dtab->map, attr); bpf_map_init_from_attr(&dtab->map, attr);
/* make sure page count doesn't overflow */
cost = (u64) sizeof(struct list_head) * num_possible_cpus();
if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) { if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries); dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries);
@ -143,17 +140,10 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
if (err) if (err)
return -EINVAL; return -EINVAL;
dtab->flush_list = alloc_percpu(struct list_head);
if (!dtab->flush_list)
goto free_charge;
for_each_possible_cpu(cpu)
INIT_LIST_HEAD(per_cpu_ptr(dtab->flush_list, cpu));
if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) { if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets); dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets);
if (!dtab->dev_index_head) if (!dtab->dev_index_head)
goto free_percpu; goto free_charge;
spin_lock_init(&dtab->index_lock); spin_lock_init(&dtab->index_lock);
} else { } else {
@ -161,13 +151,11 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
sizeof(struct bpf_dtab_netdev *), sizeof(struct bpf_dtab_netdev *),
dtab->map.numa_node); dtab->map.numa_node);
if (!dtab->netdev_map) if (!dtab->netdev_map)
goto free_percpu; goto free_charge;
} }
return 0; return 0;
free_percpu:
free_percpu(dtab->flush_list);
free_charge: free_charge:
bpf_map_charge_finish(&dtab->map.memory); bpf_map_charge_finish(&dtab->map.memory);
return -ENOMEM; return -ENOMEM;
@ -254,7 +242,6 @@ static void dev_map_free(struct bpf_map *map)
bpf_map_area_free(dtab->netdev_map); bpf_map_area_free(dtab->netdev_map);
} }
free_percpu(dtab->flush_list);
kfree(dtab); kfree(dtab);
} }
@ -384,10 +371,9 @@ static int bq_xmit_all(struct xdp_bulk_queue *bq, u32 flags)
* net device can be torn down. On devmap tear down we ensure the flush list * 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. * is empty before completing to ensure all flush operations have completed.
*/ */
void __dev_map_flush(struct bpf_map *map) void __dev_map_flush(void)
{ {
struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); struct list_head *flush_list = this_cpu_ptr(&dev_map_flush_list);
struct list_head *flush_list = this_cpu_ptr(dtab->flush_list);
struct xdp_bulk_queue *bq, *tmp; struct xdp_bulk_queue *bq, *tmp;
rcu_read_lock(); rcu_read_lock();
@ -419,7 +405,7 @@ static int bq_enqueue(struct bpf_dtab_netdev *obj, struct xdp_frame *xdpf,
struct net_device *dev_rx) struct net_device *dev_rx)
{ {
struct list_head *flush_list = this_cpu_ptr(obj->dtab->flush_list); struct list_head *flush_list = this_cpu_ptr(&dev_map_flush_list);
struct xdp_bulk_queue *bq = this_cpu_ptr(obj->bulkq); struct xdp_bulk_queue *bq = this_cpu_ptr(obj->bulkq);
if (unlikely(bq->count == DEV_MAP_BULK_SIZE)) if (unlikely(bq->count == DEV_MAP_BULK_SIZE))
@ -777,10 +763,15 @@ static struct notifier_block dev_map_notifier = {
static int __init dev_map_init(void) static int __init dev_map_init(void)
{ {
int cpu;
/* Assure tracepoint shadow struct _bpf_dtab_netdev is in sync */ /* Assure tracepoint shadow struct _bpf_dtab_netdev is in sync */
BUILD_BUG_ON(offsetof(struct bpf_dtab_netdev, dev) != BUILD_BUG_ON(offsetof(struct bpf_dtab_netdev, dev) !=
offsetof(struct _bpf_dtab_netdev, dev)); offsetof(struct _bpf_dtab_netdev, dev));
register_netdevice_notifier(&dev_map_notifier); register_netdevice_notifier(&dev_map_notifier);
for_each_possible_cpu(cpu)
INIT_LIST_HEAD(&per_cpu(dev_map_flush_list, cpu));
return 0; return 0;
} }

2
net/core/filter.c
View file

@ -3555,7 +3555,7 @@ void xdp_do_flush_map(void)
switch (map->map_type) { switch (map->map_type) {
case BPF_MAP_TYPE_DEVMAP: case BPF_MAP_TYPE_DEVMAP:
case BPF_MAP_TYPE_DEVMAP_HASH: case BPF_MAP_TYPE_DEVMAP_HASH:
__dev_map_flush(map); __dev_map_flush();
break; break;
case BPF_MAP_TYPE_CPUMAP: case BPF_MAP_TYPE_CPUMAP:
__cpu_map_flush(map); __cpu_map_flush(map);