netlink_unicast 返回 -11的问题

jinxinxin163

我在一个驱动的write函数中调用netlink_unicast发送数据给应用层程序。
刚开始的时候，是ok的，但过了一会儿之后，netlink_unicast失败，
返回值为  -11。
在include/asm-generic/errno-base.h文件中查到,11表示“try again”
大家有碰到过这个问题么？

siasjack

回复 8# jinxinxin163


    这个方法不可取

特别在处理网络数据包时，每个包都sleep一下就死定了！！

smalloc

一般任何大信息量都会阻塞消息通路。
就是进程间socket对socket也是一样。
生产者消费者问题。

Godbach

回复 11# 帅绝人寰
老帅给了例子吧


   

帅绝人寰

同学们， 从kernel往userspace发消息，除非消息量很小，否则应该用relay机制。

nehcc

回复 8# jinxinxin163


    你前面有提到 netlink 发给用户层的数据非常多
    然后 后面 却又 sleep(100) , 这样会不会延迟、堵塞 ？

jinxinxin163

http://linux.chinaunix.net/bbs/thread-1153854-1-1.html

jinxinxin163

问题的原因找到了
其实就是netlink_unicast发送的比接收端快很多，以至于"the internal buffer in the socket will get filled up"。
我尝试在驱动的write函数里在调用netlink_unicast前msleep(100),就正常了。

jinxinxin163

我在
http://lists.netfilter.org/piper ... ptember/009317.html
看到以前有个人也碰到了和我一样的问题，但是他没有解决。

I have a problem when using netlink_unicast(...) in
net/netlink/af_netlink.c. When calling netlink_unicast(...) multiple times,
e.g. in a loop, the internal buffer in the socket will get filled up, then
it will refuse to send any more netlink msg and return -EAGAIN.

Is there anyway to force netlink socket to send/flush whatever in the buffer
thus leave more room for the next netlink_unicast call?

Any advice is appreciated. thank you very much.

jinxinxin163

回复 5# emmoblin


count = 1024
send_to_user: have sent=1040
advtty_write: 1024
count = 2048
send_to_user: have sent=1040
advtty_write: 1024
count = 1024
send_to_user: have sent=1040
advtty_write: 1024
count = 2048
send_to_user: have sent=1040
advtty_write: 1024
count = 1024
send_to_user: have sent=1040
advtty_write: 1024
count = 2048
send_to_user: have sent=1040
advtty_write: 1024
count = 1024
send_to_user: have sent=1040
advtty_write: 1024
count = 2048
send_to_user: have sent=1040
advtty_write: 1024
count = 1024
send_to_user: have sent=1040
advtty_write: 1024
count = 2048
send_to_user: have sent=1040
advtty_write: 1024
count = 1024
send_to_user: have sent=1040
advtty_write: 1024
count = 2048
send_to_user: have sent=1040
advtty_write: 1024
count = 1024
send_to_user: have sent=1040
advtty_write: 1024
count = 2048
send_to_user: have sent=1040
advtty_write: 1024
count = 1024
send_to_user: have sent=1040
advtty_write: 1024
count = 2048
send_to_user: have sent=1040
advtty_write: 1024
count = 1024
send_to_user: have sent=1040
advtty_write: 1024
count = 2048
send_to_user: have sent=1040
advtty_write: 1024
count = 1024
send_to_user: have sent=1040
advtty_write: 1024
count = 2048
send_to_user: have sent=1040
advtty_write: 1024
count = 1024
send_to_user: have sent=1040
advtty_write: 1024
count = 2048
send_to_user: have sent=1040
advtty_write: 1024
count = 1024
advtty:can not unicast skb(-11)
count = 2048
advtty:can not unicast skb(-11)
count = 2048
advtty:can not unicast skb(-11)

刚开始发送是ok的，但后来就发不出去了