xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net: convert syn_wait_lock to a spinlock

Browse Source 
This is a low hanging fruit, as we'll get rid of syn_wait_lock eventually.

We hold syn_wait_lock for such small sections, that it makes no sense to use
a read/write lock. A spin lock is simply faster.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2015-03-22 10:22:21 -07:00
committed by David S. Miller
parent 8b929ab12f
commit b282705336
6 changed files with 24 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
net/ipv4/tcp_ipv4.c
View File

@@ -1909,13 +1909,13 @@ get_req:
}
sk = sk_nulls_next(st->syn_wait_sk);
st->state = TCP_SEQ_STATE_LISTENING;
read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
spin_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
} else {
icsk = inet_csk(sk);
read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
spin_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
if (reqsk_queue_len(&icsk->icsk_accept_queue))
goto start_req;
read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
spin_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
sk = sk_nulls_next(sk);
}
get_sk:
@@ -1927,7 +1927,7 @@ get_sk:
goto out;
}
icsk = inet_csk(sk);
read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
spin_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
if (reqsk_queue_len(&icsk->icsk_accept_queue)) {
start_req:
st->uid = sock_i_uid(sk);
@@ -1936,7 +1936,7 @@ start_req:
st->sbucket = 0;
goto get_req;
}
read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
spin_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
}
spin_unlock_bh(&ilb->lock);
st->offset = 0;
@@ -2155,7 +2155,7 @@ static void tcp_seq_stop(struct seq_file *seq, void *v)
case TCP_SEQ_STATE_OPENREQ:
if (v) {
struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk);
read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
spin_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
}
case TCP_SEQ_STATE_LISTENING:
if (v != SEQ_START_TOKEN)