We continuously hold the socket lock during large reads and writes. This may inflate RTT and negatively impact TCP performance. Flush the backlog periodically. I tried to pick a flush period (128kB) which gives significant benefit but the max Bps rate is not yet visibly impacted.
Signed-off-by: Jakub Kicinski kuba@kernel.org --- net/core/sock.c | 1 + net/tls/tls_sw.c | 23 +++++++++++++++++++++++ 2 files changed, 24 insertions(+)
diff --git a/net/core/sock.c b/net/core/sock.c index 92a0296ccb18..4cb957d934a2 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2870,6 +2870,7 @@ void __sk_flush_backlog(struct sock *sk) __release_sock(sk); spin_unlock_bh(&sk->sk_lock.slock); } +EXPORT_SYMBOL_GPL(__sk_flush_backlog);
/** * sk_wait_data - wait for data to arrive at sk_receive_queue diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 7592b6519953..79043bc3da39 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -1738,6 +1738,24 @@ static int process_rx_list(struct tls_sw_context_rx *ctx, return copied ? : err; }
+static void +tls_read_flush_backlog(struct sock *sk, struct tls_prot_info *prot, + size_t len_left, size_t decrypted, ssize_t done, + size_t *flushed_at) +{ + size_t max_rec; + + if (len_left <= decrypted) + return; + + max_rec = prot->overhead_size - prot->tail_size + TLS_MAX_PAYLOAD_SIZE; + if (done - *flushed_at < SZ_128K && tcp_inq(sk) > max_rec) + return; + + *flushed_at = done; + sk_flush_backlog(sk); +} + int tls_sw_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, @@ -1750,6 +1768,7 @@ int tls_sw_recvmsg(struct sock *sk, struct sk_psock *psock; unsigned char control = 0; ssize_t decrypted = 0; + size_t flushed_at = 0; struct strp_msg *rxm; struct tls_msg *tlm; struct sk_buff *skb; @@ -1839,6 +1858,10 @@ int tls_sw_recvmsg(struct sock *sk, if (err <= 0) goto recv_end;
+ /* periodically flush backlog, and feed strparser */ + tls_read_flush_backlog(sk, prot, len, to_decrypt, + decrypted + copied, &flushed_at); + ctx->recv_pkt = NULL; __strp_unpause(&ctx->strp); __skb_queue_tail(&ctx->rx_list, skb);