diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-09-19 16:27:05 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-09-19 16:32:23 -0700 |
| commit | d464e84eed02993d40ad55fdc19f4523e4deee5b (patch) | |
| tree | e7d898dbf54288fac182c63a2ec7d092082f8f44 /lib | |
| parent | 4a336a23d619e96aef37d4d054cfadcdd1b581ba (diff) | |
kobject: factorize skb setup in kobject_uevent_net_broadcast()
We can build one skb and let it be cloned in netlink.
This is much faster, and use less memory (all clones will
share the same skb->head)
Tested:
time perf record (for f in `seq 1 3000` ; do ip netns add tast$f; done)
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 4.110 MB perf.data (~179584 samples) ]
real 0m24.227s # instead of 0m52.554s
user 0m0.329s
sys 0m23.753s # instead of 0m51.375s
14.77% ip [kernel.kallsyms] [k] __ip6addrlbl_add
14.56% ip [kernel.kallsyms] [k] netlink_broadcast_filtered
11.65% ip [kernel.kallsyms] [k] netlink_has_listeners
6.19% ip [kernel.kallsyms] [k] _raw_spin_lock_irqsave
5.66% ip [kernel.kallsyms] [k] kobject_uevent_env
4.97% ip [kernel.kallsyms] [k] memset_erms
4.67% ip [kernel.kallsyms] [k] refcount_sub_and_test
4.41% ip [kernel.kallsyms] [k] _raw_read_lock
3.59% ip [kernel.kallsyms] [k] refcount_inc_not_zero
3.13% ip [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore
1.55% ip [kernel.kallsyms] [k] __wake_up
1.20% ip [kernel.kallsyms] [k] strlen
1.03% ip [kernel.kallsyms] [k] __wake_up_common
0.93% ip [kernel.kallsyms] [k] consume_skb
0.92% ip [kernel.kallsyms] [k] netlink_trim
0.87% ip [kernel.kallsyms] [k] insert_header
0.63% ip [kernel.kallsyms] [k] unmap_page_range
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/kobject_uevent.c | 34 |
1 files changed, 19 insertions, 15 deletions
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 78b2a7e378c0..147db91c10d0 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -301,23 +301,26 @@ static int kobject_uevent_net_broadcast(struct kobject *kobj, { int retval = 0; #if defined(CONFIG_NET) + struct sk_buff *skb = NULL; struct uevent_sock *ue_sk; /* send netlink message */ list_for_each_entry(ue_sk, &uevent_sock_list, list) { struct sock *uevent_sock = ue_sk->sk; - struct sk_buff *skb; - size_t len; if (!netlink_has_listeners(uevent_sock, 1)) continue; - /* allocate message with the maximum possible size */ - len = strlen(action_string) + strlen(devpath) + 2; - skb = alloc_skb(len + env->buflen, GFP_KERNEL); - if (skb) { + if (!skb) { + /* allocate message with the maximum possible size */ + size_t len = strlen(action_string) + strlen(devpath) + 2; char *scratch; + retval = -ENOMEM; + skb = alloc_skb(len + env->buflen, GFP_KERNEL); + if (!skb) + continue; + /* add header */ scratch = skb_put(skb, len); sprintf(scratch, "%s@%s", action_string, devpath); @@ -325,16 +328,17 @@ static int kobject_uevent_net_broadcast(struct kobject *kobj, skb_put_data(skb, env->buf, env->buflen); NETLINK_CB(skb).dst_group = 1; - retval = netlink_broadcast_filtered(uevent_sock, skb, - 0, 1, GFP_KERNEL, - kobj_bcast_filter, - kobj); - /* ENOBUFS should be handled in userspace */ - if (retval == -ENOBUFS || retval == -ESRCH) - retval = 0; - } else - retval = -ENOMEM; + } + + retval = netlink_broadcast_filtered(uevent_sock, skb_get(skb), + 0, 1, GFP_KERNEL, + kobj_bcast_filter, + kobj); + /* ENOBUFS should be handled in userspace */ + if (retval == -ENOBUFS || retval == -ESRCH) + retval = 0; } + consume_skb(skb); #endif return retval; } |