From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Ellerman Subject: [PATCH 5/18] iseries_veth: Remove redundant message stack lock Date: Thu, 1 Sep 2005 11:29:05 +1000 (EST) Message-ID: <20050901012905.C9D3668205@ozlabs.org> References: <1125538127.859382.875909607846.qpush@concordia> Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc64-dev@ozlabs.org Return-path: To: In-Reply-To: <1125538127.859382.875909607846.qpush@concordia> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc64-dev-bounces@ozlabs.org Errors-To: linuxppc64-dev-bounces@ozlabs.org List-Id: netdev.vger.kernel.org The iseries_veth driver keeps a stack of messages for each connection and a lock to protect the stack. However there is also a per-connection lock which makes the message stack lock redundant. Remove the message stack lock and document the fact that callers of the stack-manipulation functions must hold the connection's lock. Signed-off-by: Michael Ellerman --- drivers/net/iseries_veth.c | 12 +++--------- 1 files changed, 3 insertions(+), 9 deletions(-) Index: veth-dev2/drivers/net/iseries_veth.c =================================================================== --- veth-dev2.orig/drivers/net/iseries_veth.c +++ veth-dev2/drivers/net/iseries_veth.c @@ -143,7 +143,6 @@ struct veth_lpar_connection { struct VethCapData remote_caps; u32 ack_timeout; - spinlock_t msg_stack_lock; struct veth_msg *msg_stack_head; }; @@ -190,27 +189,23 @@ static void veth_timed_ack(unsigned long #define veth_debug(fmt, args...) do {} while (0) #endif +/* You must hold the connection's lock when you call this function. */ static inline void veth_stack_push(struct veth_lpar_connection *cnx, struct veth_msg *msg) { - unsigned long flags; - - spin_lock_irqsave(&cnx->msg_stack_lock, flags); msg->next = cnx->msg_stack_head; cnx->msg_stack_head = msg; - spin_unlock_irqrestore(&cnx->msg_stack_lock, flags); } +/* You must hold the connection's lock when you call this function. */ static inline struct veth_msg *veth_stack_pop(struct veth_lpar_connection *cnx) { - unsigned long flags; struct veth_msg *msg; - spin_lock_irqsave(&cnx->msg_stack_lock, flags); msg = cnx->msg_stack_head; if (msg) cnx->msg_stack_head = cnx->msg_stack_head->next; - spin_unlock_irqrestore(&cnx->msg_stack_lock, flags); + return msg; } @@ -645,7 +640,6 @@ static int veth_init_connection(u8 rlp) cnx->msgs = msgs; memset(msgs, 0, VETH_NUMBUFFERS * sizeof(struct veth_msg)); - spin_lock_init(&cnx->msg_stack_lock); for (i = 0; i < VETH_NUMBUFFERS; i++) { msgs[i].token = i;