From patchwork Wed Dec 17 14:07:52 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?R=C3=A9mi_Denis-Courmont?= X-Patchwork-Id: 14493 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id B050BDDF3E for ; Thu, 18 Dec 2008 01:08:15 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751511AbYLQOIL (ORCPT ); Wed, 17 Dec 2008 09:08:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751489AbYLQOIJ (ORCPT ); Wed, 17 Dec 2008 09:08:09 -0500 Received: from smtp.nokia.com ([192.100.105.134]:44508 "EHLO mgw-mx09.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751411AbYLQOIH (ORCPT ); Wed, 17 Dec 2008 09:08:07 -0500 Received: from esebh105.NOE.Nokia.com (esebh105.ntc.nokia.com [172.21.138.211]) by mgw-mx09.nokia.com (Switch-3.2.6/Switch-3.2.6) with ESMTP id mBHE6Wcb015297 for ; Wed, 17 Dec 2008 08:08:04 -0600 Received: from esebh102.NOE.Nokia.com ([172.21.138.183]) by esebh105.NOE.Nokia.com with Microsoft SMTPSVC(6.0.3790.3959); Wed, 17 Dec 2008 16:07:59 +0200 Received: from mgw-int02.ntc.nokia.com ([172.21.143.97]) by esebh102.NOE.Nokia.com over TLS secured channel with Microsoft SMTPSVC(6.0.3790.3959); Wed, 17 Dec 2008 16:07:58 +0200 Received: from localhost.localdomain (esdhcp041160.research.nokia.com [172.21.41.160]) by mgw-int02.ntc.nokia.com (Switch-3.2.5/Switch-3.2.5) with ESMTP id mBHE7sdd016910 for ; Wed, 17 Dec 2008 16:07:57 +0200 From: =?utf-8?q?R=C3=A9mi=20Denis-Courmont?= To: netdev@vger.kernel.org Subject: [PATCH 3/5] Phonet: use atomic for packet TX window Date: Wed, 17 Dec 2008 16:07:52 +0200 Message-Id: <1229522874-20636-3-git-send-email-remi.denis-courmont@nokia.com> X-Mailer: git-send-email 1.5.4.3 In-Reply-To: <200812171607.14184.remi.denis-courmont@nokia.com> References: <200812171607.14184.remi.denis-courmont@nokia.com> MIME-Version: 1.0 X-OriginalArrivalTime: 17 Dec 2008 14:07:58.0617 (UTC) FILETIME=[DD79D890:01C96050] X-Nokia-AV: Clean Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org GPRS TX flow control won't need to lock the underlying socket anymore. Signed-off-by: Rémi Denis-Courmont --- include/net/phonet/pep.h | 2 +- net/phonet/pep.c | 38 +++++++++++++++++++++----------------- net/phonet/socket.c | 2 +- 3 files changed, 23 insertions(+), 19 deletions(-) diff --git a/include/net/phonet/pep.h b/include/net/phonet/pep.h index fcd7930..4c61cdc 100644 --- a/include/net/phonet/pep.h +++ b/include/net/phonet/pep.h @@ -35,12 +35,12 @@ struct pep_sock { struct sock *listener; struct sk_buff_head ctrlreq_queue; #define PNPIPE_CTRLREQ_MAX 10 + atomic_t tx_credits; int ifindex; u16 peer_type; /* peer type/subtype */ u8 pipe_handle; u8 rx_credits; - u8 tx_credits; u8 rx_fc; /* RX flow control */ u8 tx_fc; /* TX flow control */ u8 init_enable; /* auto-enable at creation */ diff --git a/net/phonet/pep.c b/net/phonet/pep.c index bc6d50f..bb3e678 100644 --- a/net/phonet/pep.c +++ b/net/phonet/pep.c @@ -225,6 +225,7 @@ static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb) { struct pep_sock *pn = pep_sk(sk); struct pnpipehdr *hdr = pnp_hdr(skb); + int wake = 0; if (!pskb_may_pull(skb, sizeof(*hdr) + 4)) return -EINVAL; @@ -241,16 +242,16 @@ static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb) case PN_LEGACY_FLOW_CONTROL: switch (hdr->data[4]) { case PEP_IND_BUSY: - pn->tx_credits = 0; + atomic_set(&pn->tx_credits, 0); break; case PEP_IND_READY: - pn->tx_credits = 1; + atomic_set(&pn->tx_credits, wake = 1); break; } break; case PN_ONE_CREDIT_FLOW_CONTROL: if (hdr->data[4] == PEP_IND_READY) - pn->tx_credits = 1; + atomic_set(&pn->tx_credits, wake = 1); break; } break; @@ -258,10 +259,7 @@ static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb) case PN_PEP_IND_ID_MCFC_GRANT_CREDITS: if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL) break; - if (pn->tx_credits + hdr->data[4] > 0xff) - pn->tx_credits = 0xff; - else - pn->tx_credits += hdr->data[4]; + atomic_add(wake = hdr->data[4], &pn->tx_credits); break; default: @@ -269,7 +267,7 @@ static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb) (unsigned)hdr->data[1]); return -EOPNOTSUPP; } - if (pn->tx_credits) + if (wake) sk->sk_write_space(sk); return 0; } @@ -343,7 +341,7 @@ static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb) } /* fall through */ case PNS_PEP_DISABLE_REQ: - pn->tx_credits = 0; + atomic_set(&pn->tx_credits, 0); pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC); break; @@ -390,7 +388,7 @@ static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb) /* fall through */ case PNS_PIPE_ENABLED_IND: if (!pn_flow_safe(pn->tx_fc)) { - pn->tx_credits = 1; + atomic_set(&pn->tx_credits, 1); sk->sk_write_space(sk); } if (sk->sk_state == TCP_ESTABLISHED) @@ -504,8 +502,9 @@ static int pep_connreq_rcv(struct sock *sk, struct sk_buff *skb) newpn->pn_sk.resource = pn->pn_sk.resource; skb_queue_head_init(&newpn->ctrlreq_queue); newpn->pipe_handle = pipe_handle; + atomic_set(&newpn->tx_credits, 0); newpn->peer_type = peer_type; - newpn->rx_credits = newpn->tx_credits = 0; + newpn->rx_credits = 0; newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL; newpn->init_enable = enabled; @@ -821,14 +820,18 @@ static int pipe_skb_send(struct sock *sk, struct sk_buff *skb) struct pep_sock *pn = pep_sk(sk); struct pnpipehdr *ph; + if (pn_flow_safe(pn->tx_fc) && + !atomic_add_unless(&pn->tx_credits, -1, 0)) { + kfree_skb(skb); + return -ENOBUFS; + } + skb_push(skb, 3); skb_reset_transport_header(skb); ph = pnp_hdr(skb); ph->utid = 0; ph->message_id = PNS_PIPE_DATA; ph->pipe_handle = pn->pipe_handle; - if (pn_flow_safe(pn->tx_fc) && pn->tx_credits) - pn->tx_credits--; return pn_skb_send(sk, skb, &pipe_srv); } @@ -866,7 +869,7 @@ disabled: BUG_ON(sk->sk_state != TCP_ESTABLISHED); /* Wait until flow control allows TX */ - done = pn->tx_credits > 0; + done = atomic_read(&pn->tx_credits); while (!done) { DEFINE_WAIT(wait); @@ -881,7 +884,7 @@ disabled: prepare_to_wait(&sk->sk_socket->wait, &wait, TASK_INTERRUPTIBLE); - done = sk_wait_event(sk, &timeo, pn->tx_credits > 0); + done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits)); finish_wait(&sk->sk_socket->wait, &wait); if (sk->sk_state != TCP_ESTABLISHED) @@ -895,7 +898,8 @@ disabled: goto out; skb_reserve(skb, MAX_PHONET_HEADER + 3); - if (sk->sk_state != TCP_ESTABLISHED || !pn->tx_credits) + if (sk->sk_state != TCP_ESTABLISHED || + !atomic_read(&pn->tx_credits)) goto disabled; /* sock_alloc_send_skb might sleep */ } @@ -917,7 +921,7 @@ int pep_writeable(struct sock *sk) { struct pep_sock *pn = pep_sk(sk); - return (sk->sk_state == TCP_ESTABLISHED) ? pn->tx_credits : 0; + return atomic_read(&pn->tx_credits); } int pep_write(struct sock *sk, struct sk_buff *skb) diff --git a/net/phonet/socket.c b/net/phonet/socket.c index c75aa5c..ada2a35 100644 --- a/net/phonet/socket.c +++ b/net/phonet/socket.c @@ -227,7 +227,7 @@ static unsigned int pn_socket_poll(struct file *file, struct socket *sock, if (!mask && sk->sk_state == TCP_CLOSE_WAIT) return POLLHUP; - if (sk->sk_state == TCP_ESTABLISHED && pn->tx_credits) + if (sk->sk_state == TCP_ESTABLISHED && atomic_read(&pn->tx_credits)) mask |= POLLOUT | POLLWRNORM | POLLWRBAND; return mask;