From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Nicholas A. Bellinger" Subject: [PATCH 4/9] target: Avoid extra t_state_lock access in __target_execute_cmd Date: Fri, 7 Jun 2013 21:34:19 +0000 Message-ID: <1370640864-15568-5-git-send-email-nab@linux-iscsi.org> References: <1370640864-15568-1-git-send-email-nab@linux-iscsi.org> Return-path: Received: from mail.linux-iscsi.org ([67.23.28.174]:48599 "EHLO linux-iscsi.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756072Ab3FGVry (ORCPT ); Fri, 7 Jun 2013 17:47:54 -0400 In-Reply-To: <1370640864-15568-1-git-send-email-nab@linux-iscsi.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: target-devel Cc: linux-scsi , Christoph Hellwig , Roland Dreier , Kent Overstreet , Asias He , "Michael S. Tsirkin" , Or Gerlitz , Moussa Ba , Nicholas Bellinger From: Nicholas Bellinger This patch makes target_execute_cmd() set CMD_T_BUSY|CMD_T_SENT while holding se_cmd->t_state_lock, in order to avoid the extra aquire/release in __target_execute_cmd(). It also clears these bits in case of a target_handle_task_attr() failure. Cc: Christoph Hellwig Cc: Roland Dreier Cc: Kent Overstreet Cc: Or Gerlitz Cc: Moussa Ba Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 16 +++++++++------- 1 files changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index daa7aa8..f9e69f5 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -1579,10 +1579,6 @@ static void __target_execute_cmd(struct se_cmd *cmd) { sense_reason_t ret; - spin_lock_irq(&cmd->t_state_lock); - cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT); - spin_unlock_irq(&cmd->t_state_lock); - if (cmd->execute_cmd) { ret = cmd->execute_cmd(cmd); if (ret) { @@ -1689,11 +1685,17 @@ void target_execute_cmd(struct se_cmd *cmd) } cmd->t_state = TRANSPORT_PROCESSING; - cmd->transport_state |= CMD_T_ACTIVE; + cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT; spin_unlock_irq(&cmd->t_state_lock); - if (!target_handle_task_attr(cmd)) - __target_execute_cmd(cmd); + if (target_handle_task_attr(cmd)) { + spin_lock_irq(&cmd->t_state_lock); + cmd->transport_state &= ~CMD_T_BUSY|CMD_T_SENT; + spin_unlock_irq(&cmd->t_state_lock); + return; + } + + __target_execute_cmd(cmd); } EXPORT_SYMBOL(target_execute_cmd); -- 1.7.2.5