linux-kernel - [PATCH v2 2/2] scsi: fnic: Remove unnecessary spinlock locking and unlocking

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Message-ID: <20250301013712.3115-2-kartilak@cisco.com>
Date: Fri, 28 Feb 2025 17:37:12 -0800
From: Karan Tilak Kumar <kartilak@...co.com>
To: sebaddel@...co.com
Cc: arulponn@...co.com,
	djhawar@...co.com,
	gcboffa@...co.com,
	mkai2@...co.com,
	satishkh@...co.com,
	aeasi@...co.com,
	jejb@...ux.ibm.com,
	martin.petersen@...cle.com,
	linux-scsi@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Karan Tilak Kumar <kartilak@...co.com>,
	Dan Carpenter <dan.carpenter@...aro.org>
Subject: [PATCH v2 2/2] scsi: fnic: Remove unnecessary spinlock locking and unlocking

Remove unnecessary locking and unlocking of spinlock in
fdls_schedule_oxid_free_retry_work.
This will shorten the time in the critical section.

Suggested-by: Dan Carpenter <dan.carpenter@...aro.org>
Fixes: a63e78eb2b0f ("scsi: fnic: Add support for fabric based solicited requests and responses")
Reviewed-by: Sesidhar Baddela <sebaddel@...co.com>
Reviewed-by: Arulprabhu Ponnusamy <arulponn@...co.com>
Reviewed-by: Gian Carlo Boffa <gcboffa@...co.com>
Reviewed-by: Arun Easi <aeasi@...co.com>
Tested-by: Karan Tilak Kumar <kartilak@...co.com>
Signed-off-by: Karan Tilak Kumar <kartilak@...co.com>
---
Changes between v1 and v2:
    Incorporate review comments by Dan:
	Replace test and clear bit with clear bit.
---
 drivers/scsi/fnic/fdls_disc.c | 24 +++++++-----------------
 1 file changed, 7 insertions(+), 17 deletions(-)

diff --git a/drivers/scsi/fnic/fdls_disc.c b/drivers/scsi/fnic/fdls_disc.c
index 8843d9486dbb..a9ffa7b63730 100644
--- a/drivers/scsi/fnic/fdls_disc.c
+++ b/drivers/scsi/fnic/fdls_disc.c
@@ -311,36 +311,26 @@ void fdls_schedule_oxid_free_retry_work(struct work_struct *work)
 	unsigned long flags;
 	int idx;
 
-	spin_lock_irqsave(&fnic->fnic_lock, flags);
-
 	for_each_set_bit(idx, oxid_pool->pending_schedule_free, FNIC_OXID_POOL_SZ) {
 
 		FNIC_FCS_DBG(KERN_INFO, fnic->host, fnic->fnic_num,
 			"Schedule oxid free. oxid idx: %d\n", idx);
 
-		spin_unlock_irqrestore(&fnic->fnic_lock, flags);
 		reclaim_entry = kzalloc(sizeof(*reclaim_entry), GFP_KERNEL);
-		spin_lock_irqsave(&fnic->fnic_lock, flags);
-
 		if (!reclaim_entry) {
 			schedule_delayed_work(&oxid_pool->schedule_oxid_free_retry,
 				msecs_to_jiffies(SCHEDULE_OXID_FREE_RETRY_TIME));
-			spin_unlock_irqrestore(&fnic->fnic_lock, flags);
 			return;
 		}
 
-		if (test_and_clear_bit(idx, oxid_pool->pending_schedule_free)) {
-			reclaim_entry->oxid_idx = idx;
-			reclaim_entry->expires = round_jiffies(jiffies + delay_j);
-			list_add_tail(&reclaim_entry->links, &oxid_pool->oxid_reclaim_list);
-			schedule_delayed_work(&oxid_pool->oxid_reclaim_work, delay_j);
-		} else {
-			/* unlikely scenario, free the allocated memory and continue */
-			kfree(reclaim_entry);
-		}
+		clear_bit(idx, oxid_pool->pending_schedule_free);
+		reclaim_entry->oxid_idx = idx;
+		reclaim_entry->expires = round_jiffies(jiffies + delay_j);
+		spin_lock_irqsave(&fnic->fnic_lock, flags);
+		list_add_tail(&reclaim_entry->links, &oxid_pool->oxid_reclaim_list);
+		spin_unlock_irqrestore(&fnic->fnic_lock, flags);
+		schedule_delayed_work(&oxid_pool->oxid_reclaim_work, delay_j);
 	}
-
-	spin_unlock_irqrestore(&fnic->fnic_lock, flags);
 }
 
 static bool fdls_is_oxid_fabric_req(uint16_t oxid)
-- 
2.47.1