[SCSI] lpfc 8.3.39: Reduced spinlock contention on SCSI buffer list

Signed-off-by: James Smart <james.smart@emulex.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 38 insertions, 16 deletions

diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 7bb89f4..207d3ec 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -911,9 +911,9 @@ lpfc_hba_down_post_s4(struct lpfc_hba *phba)
 		psb->pCmd = NULL;
 		psb->status = IOSTAT_SUCCESS;
 	}
-	spin_lock_irqsave(&phba->scsi_buf_list_lock, iflag);
-	list_splice(&aborts, &phba->lpfc_scsi_buf_list);
-	spin_unlock_irqrestore(&phba->scsi_buf_list_lock, iflag);
+	spin_lock_irqsave(&phba->scsi_buf_list_put_lock, iflag);
+	list_splice(&aborts, &phba->lpfc_scsi_buf_list_put);
+	spin_unlock_irqrestore(&phba->scsi_buf_list_put_lock, iflag);
 	return 0;
 }
 
@@ -2854,16 +2854,30 @@ lpfc_scsi_free(struct lpfc_hba *phba)
 	struct lpfc_iocbq *io, *io_next;
 
 	spin_lock_irq(&phba->hbalock);
+
 	/* Release all the lpfc_scsi_bufs maintained by this host. */
-	spin_lock(&phba->scsi_buf_list_lock);
-	list_for_each_entry_safe(sb, sb_next, &phba->lpfc_scsi_buf_list, list) {
+
+	spin_lock(&phba->scsi_buf_list_put_lock);
+	list_for_each_entry_safe(sb, sb_next, &phba->lpfc_scsi_buf_list_put,
+				 list) {
+		list_del(&sb->list);
+		pci_pool_free(phba->lpfc_scsi_dma_buf_pool, sb->data,
+			      sb->dma_handle);
+		kfree(sb);
+		phba->total_scsi_bufs--;
+	}
+	spin_unlock(&phba->scsi_buf_list_put_lock);
+
+	spin_lock(&phba->scsi_buf_list_get_lock);
+	list_for_each_entry_safe(sb, sb_next, &phba->lpfc_scsi_buf_list_get,
+				 list) {
 		list_del(&sb->list);
 		pci_pool_free(phba->lpfc_scsi_dma_buf_pool, sb->data,
 			      sb->dma_handle);
 		kfree(sb);
 		phba->total_scsi_bufs--;
 	}
-	spin_unlock(&phba->scsi_buf_list_lock);
+	spin_unlock(&phba->scsi_buf_list_get_lock);
 
 	/* Release all the lpfc_iocbq entries maintained by this host. */
 	list_for_each_entry_safe(io, io_next, &phba->lpfc_iocb_list, list) {
@@ -2999,9 +3013,12 @@ lpfc_sli4_xri_sgl_update(struct lpfc_hba *phba)
 			phba->sli4_hba.scsi_xri_cnt,
 			phba->sli4_hba.scsi_xri_max);
 
-	spin_lock_irq(&phba->scsi_buf_list_lock);
-	list_splice_init(&phba->lpfc_scsi_buf_list, &scsi_sgl_list);
-	spin_unlock_irq(&phba->scsi_buf_list_lock);
+	spin_lock_irq(&phba->scsi_buf_list_get_lock);
+	spin_lock_irq(&phba->scsi_buf_list_put_lock);
+	list_splice_init(&phba->lpfc_scsi_buf_list_get, &scsi_sgl_list);
+	list_splice(&phba->lpfc_scsi_buf_list_put, &scsi_sgl_list);
+	spin_unlock_irq(&phba->scsi_buf_list_put_lock);
+	spin_unlock_irq(&phba->scsi_buf_list_get_lock);
 
 	if (phba->sli4_hba.scsi_xri_cnt > phba->sli4_hba.scsi_xri_max) {
 		/* max scsi xri shrinked below the allocated scsi buffers */
@@ -3015,9 +3032,9 @@ lpfc_sli4_xri_sgl_update(struct lpfc_hba *phba)
 				      psb->dma_handle);
 			kfree(psb);
 		}
-		spin_lock_irq(&phba->scsi_buf_list_lock);
+		spin_lock_irq(&phba->scsi_buf_list_get_lock);
 		phba->sli4_hba.scsi_xri_cnt -= scsi_xri_cnt;
-		spin_unlock_irq(&phba->scsi_buf_list_lock);
+		spin_unlock_irq(&phba->scsi_buf_list_get_lock);
 	}
 
 	/* update xris associated to remaining allocated scsi buffers */
@@ -3035,9 +3052,12 @@ lpfc_sli4_xri_sgl_update(struct lpfc_hba *phba)
 		psb->cur_iocbq.sli4_lxritag = lxri;
 		psb->cur_iocbq.sli4_xritag = phba->sli4_hba.xri_ids[lxri];
 	}
-	spin_lock_irq(&phba->scsi_buf_list_lock);
-	list_splice_init(&scsi_sgl_list, &phba->lpfc_scsi_buf_list);
-	spin_unlock_irq(&phba->scsi_buf_list_lock);
+	spin_lock_irq(&phba->scsi_buf_list_get_lock);
+	spin_lock_irq(&phba->scsi_buf_list_put_lock);
+	list_splice_init(&scsi_sgl_list, &phba->lpfc_scsi_buf_list_get);
+	INIT_LIST_HEAD(&phba->lpfc_scsi_buf_list_put);
+	spin_unlock_irq(&phba->scsi_buf_list_put_lock);
+	spin_unlock_irq(&phba->scsi_buf_list_get_lock);
 
 	return 0;
 
@@ -5334,8 +5354,10 @@ lpfc_setup_driver_resource_phase1(struct lpfc_hba *phba)
 	init_waitqueue_head(&phba->work_waitq);
 
 	/* Initialize the scsi buffer list used by driver for scsi IO */
-	spin_lock_init(&phba->scsi_buf_list_lock);
-	INIT_LIST_HEAD(&phba->lpfc_scsi_buf_list);
+	spin_lock_init(&phba->scsi_buf_list_get_lock);
+	INIT_LIST_HEAD(&phba->lpfc_scsi_buf_list_get);
+	spin_lock_init(&phba->scsi_buf_list_put_lock);
+	INIT_LIST_HEAD(&phba->lpfc_scsi_buf_list_put);
 
 	/* Initialize the fabric iocb list */
 	INIT_LIST_HEAD(&phba->fabric_iocb_list);