From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Love Subject: [PATCH 05/11] libfc: Move host_lock usage into ramp_up/down routines Date: Fri, 01 Apr 2011 16:06:14 -0700 Message-ID: <20110401230614.15001.77059.stgit@localhost6.localdomain6> References: <20110401230548.15001.2009.stgit@localhost6.localdomain6> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mga11.intel.com ([192.55.52.93]:17623 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752091Ab1DAXGP (ORCPT ); Fri, 1 Apr 2011 19:06:15 -0400 In-Reply-To: <20110401230548.15001.2009.stgit@localhost6.localdomain6> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James.Bottomley@suse.de, linux-scsi@vger.kernel.org Cc: Ross Brattain The host_lock is still used to protect the can_queue value in the Scsi_Host, but it doesn't need to be held and released by each caller. This patch moves the lock usage into the fc_fcp_can_queue_ramp_up and fc_fcp_can_queue_ramp_down routines. Signed-off-by: Robert Love Tested-by: Ross Brattain --- drivers/scsi/libfc/fc_fcp.c | 25 +++++++++++++++---------- 1 files changed, 15 insertions(+), 10 deletions(-) diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c index b1b03af..92ba9f0 100644 --- a/drivers/scsi/libfc/fc_fcp.c +++ b/drivers/scsi/libfc/fc_fcp.c @@ -335,22 +335,23 @@ static void fc_fcp_ddp_done(struct fc_fcp_pkt *fsp) /** * fc_fcp_can_queue_ramp_up() - increases can_queue * @lport: lport to ramp up can_queue - * - * Locking notes: Called with Scsi_Host lock held */ static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport) { struct fc_fcp_internal *si = fc_get_scsi_internal(lport); + unsigned long flags; int can_queue; + spin_lock_irqsave(lport->host->host_lock, flags); + if (si->last_can_queue_ramp_up_time && (time_before(jiffies, si->last_can_queue_ramp_up_time + FC_CAN_QUEUE_PERIOD))) - return; + goto unlock; if (time_before(jiffies, si->last_can_queue_ramp_down_time + FC_CAN_QUEUE_PERIOD)) - return; + goto unlock; si->last_can_queue_ramp_up_time = jiffies; @@ -362,6 +363,9 @@ static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport) lport->host->can_queue = can_queue; shost_printk(KERN_ERR, lport->host, "libfc: increased " "can_queue to %d.\n", can_queue); + +unlock: + spin_unlock_irqrestore(lport->host->host_lock, flags); } /** @@ -373,18 +377,19 @@ static void fc_fcp_can_queue_ramp_up(struct fc_lport *lport) * commands complete or timeout, then try again with a reduced * can_queue. Eventually we will hit the point where we run * on all reserved structs. - * - * Locking notes: Called with Scsi_Host lock held */ static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport) { struct fc_fcp_internal *si = fc_get_scsi_internal(lport); + unsigned long flags; int can_queue; + spin_lock_irqsave(lport->host->host_lock, flags); + if (si->last_can_queue_ramp_down_time && (time_before(jiffies, si->last_can_queue_ramp_down_time + FC_CAN_QUEUE_PERIOD))) - return; + goto unlock; si->last_can_queue_ramp_down_time = jiffies; @@ -395,6 +400,9 @@ static void fc_fcp_can_queue_ramp_down(struct fc_lport *lport) lport->host->can_queue = can_queue; shost_printk(KERN_ERR, lport->host, "libfc: Could not allocate frame.\n" "Reducing can_queue to %d.\n", can_queue); + +unlock: + spin_unlock_irqrestore(lport->host->host_lock, flags); } /* @@ -409,16 +417,13 @@ static inline struct fc_frame *fc_fcp_frame_alloc(struct fc_lport *lport, size_t len) { struct fc_frame *fp; - unsigned long flags; fp = fc_frame_alloc(lport, len); if (likely(fp)) return fp; /* error case */ - spin_lock_irqsave(lport->host->host_lock, flags); fc_fcp_can_queue_ramp_down(lport); - spin_unlock_irqrestore(lport->host->host_lock, flags); return NULL; }