From: Gerrit Renker Date: Sun, 25 Nov 2007 00:09:35 +0000 (-0200) Subject: [CCID2]: Remove redundant synchronisation variable X-Git-Tag: v2.6.25-rc1~1162^2~1342 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=83399361c30f2ffae20ee348ba9ada9a856d499a;p=linux-2.6 [CCID2]: Remove redundant synchronisation variable This removes the synchronisation variable `ccid2hctx_sendwait', which is set to 1 when the CCID2 sender may send a new packet, and which is set to 0 otherwise The variable is redundant, since it is only used in combination with the hc_tx_send_packet/ hc_tx_packet_sent function pair. Both functions are called under socket lock, so the following happens when the CCID2 may send a new packet: * it sets sendwait = 1 in tx_send_packet and returns 0; * the subsequent call to tx_packet_sent clears the sendwait flag; * since tx_send_packet returns 0 if and only if sendwait == 1, the BUG_ON condition in tx_packet_sent is never satisfied, since that function is never called when tx_send_packet returns a value different from 0 (cf. dccp_write_xmit); * the call to tx_packet_sent clears the flag so that the condition "!sendwait" is true the next time tx_packet_sent is called. In other words, it is sufficient to just return 0 / not-0 to synchronise tx_send_packet and tx_packet_sent -- which is what the patch does. Signed-off-by: Gerrit Renker Acked-by: Ian McDonald Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c index 2d1b7e30a7..4f6c35261b 100644 --- a/net/dccp/ccids/ccid2.c +++ b/net/dccp/ccids/ccid2.c @@ -126,13 +126,8 @@ static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) { struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); - if (hctx->ccid2hctx_pipe < hctx->ccid2hctx_cwnd) { - /* OK we can send... make sure previous packet was sent off */ - if (!hctx->ccid2hctx_sendwait) { - hctx->ccid2hctx_sendwait = 1; - return 0; - } - } + if (hctx->ccid2hctx_pipe < hctx->ccid2hctx_cwnd) + return 0; return 1; /* XXX CCID should dequeue when ready instead of polling */ } @@ -236,8 +231,6 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) struct ccid2_seq *next; u64 seq; - BUG_ON(!hctx->ccid2hctx_sendwait); - hctx->ccid2hctx_sendwait = 0; hctx->ccid2hctx_pipe++; /* There is an issue. What if another packet is sent between diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h index bc659f00cb..2671f8ebe2 100644 --- a/net/dccp/ccids/ccid2.h +++ b/net/dccp/ccids/ccid2.h @@ -66,7 +66,6 @@ struct ccid2_hc_tx_sock { struct timer_list ccid2hctx_rtotimer; u64 ccid2hctx_rpseq; int ccid2hctx_rpdupack; - int ccid2hctx_sendwait; unsigned long ccid2hctx_last_cong; u64 ccid2hctx_high_ack; };