[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>
diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index c79b4dc..be11bb9 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -899,9 +899,12 @@
int num_posted, rc = 0;
/* get all SCSI buffers need to repost to a local list */
- spin_lock_irq(&phba->scsi_buf_list_lock);
- list_splice_init(&phba->lpfc_scsi_buf_list, &post_sblist);
- 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, &post_sblist);
+ list_splice(&phba->lpfc_scsi_buf_list_put, &post_sblist);
+ spin_unlock_irq(&phba->scsi_buf_list_put_lock);
+ spin_unlock_irq(&phba->scsi_buf_list_get_lock);
/* post the list of scsi buffer sgls to port if available */
if (!list_empty(&post_sblist)) {
@@ -1053,9 +1056,9 @@
/* add the scsi buffer to a post list */
list_add_tail(&psb->list, &post_sblist);
- spin_lock_irq(&phba->scsi_buf_list_lock);
+ spin_lock_irq(&phba->scsi_buf_list_get_lock);
phba->sli4_hba.scsi_xri_cnt++;
- spin_unlock_irq(&phba->scsi_buf_list_lock);
+ spin_unlock_irq(&phba->scsi_buf_list_get_lock);
}
lpfc_printf_log(phba, KERN_INFO, LOG_BG,
"3021 Allocate %d out of %d requested new SCSI "
@@ -1104,17 +1107,23 @@
lpfc_get_scsi_buf_s3(struct lpfc_hba *phba, struct lpfc_nodelist *ndlp)
{
struct lpfc_scsi_buf * lpfc_cmd = NULL;
- struct list_head *scsi_buf_list = &phba->lpfc_scsi_buf_list;
- unsigned long iflag = 0;
+ struct list_head *scsi_buf_list_get = &phba->lpfc_scsi_buf_list_get;
+ unsigned long gflag = 0;
+ unsigned long pflag = 0;
- spin_lock_irqsave(&phba->scsi_buf_list_lock, iflag);
- list_remove_head(scsi_buf_list, lpfc_cmd, struct lpfc_scsi_buf, list);
- if (lpfc_cmd) {
- lpfc_cmd->seg_cnt = 0;
- lpfc_cmd->nonsg_phys = 0;
- lpfc_cmd->prot_seg_cnt = 0;
+ spin_lock_irqsave(&phba->scsi_buf_list_get_lock, gflag);
+ list_remove_head(scsi_buf_list_get, lpfc_cmd, struct lpfc_scsi_buf,
+ list);
+ if (!lpfc_cmd) {
+ spin_lock_irqsave(&phba->scsi_buf_list_put_lock, pflag);
+ list_splice(&phba->lpfc_scsi_buf_list_put,
+ &phba->lpfc_scsi_buf_list_get);
+ INIT_LIST_HEAD(&phba->lpfc_scsi_buf_list_put);
+ list_remove_head(scsi_buf_list_get, lpfc_cmd,
+ struct lpfc_scsi_buf, list);
+ spin_unlock_irqrestore(&phba->scsi_buf_list_put_lock, pflag);
}
- spin_unlock_irqrestore(&phba->scsi_buf_list_lock, iflag);
+ spin_unlock_irqrestore(&phba->scsi_buf_list_get_lock, gflag);
return lpfc_cmd;
}
/**
@@ -1132,28 +1141,39 @@
lpfc_get_scsi_buf_s4(struct lpfc_hba *phba, struct lpfc_nodelist *ndlp)
{
struct lpfc_scsi_buf *lpfc_cmd ;
- unsigned long iflag = 0;
+ unsigned long gflag = 0;
+ unsigned long pflag = 0;
int found = 0;
- spin_lock_irqsave(&phba->scsi_buf_list_lock, iflag);
- list_for_each_entry(lpfc_cmd, &phba->lpfc_scsi_buf_list,
- list) {
+ spin_lock_irqsave(&phba->scsi_buf_list_get_lock, gflag);
+ list_for_each_entry(lpfc_cmd, &phba->lpfc_scsi_buf_list_get, list) {
if (lpfc_test_rrq_active(phba, ndlp,
lpfc_cmd->cur_iocbq.sli4_lxritag))
continue;
list_del(&lpfc_cmd->list);
found = 1;
- lpfc_cmd->seg_cnt = 0;
- lpfc_cmd->nonsg_phys = 0;
- lpfc_cmd->prot_seg_cnt = 0;
break;
}
- spin_unlock_irqrestore(&phba->scsi_buf_list_lock,
- iflag);
+ if (!found) {
+ spin_lock_irqsave(&phba->scsi_buf_list_put_lock, pflag);
+ list_splice(&phba->lpfc_scsi_buf_list_put,
+ &phba->lpfc_scsi_buf_list_get);
+ INIT_LIST_HEAD(&phba->lpfc_scsi_buf_list_put);
+ spin_unlock_irqrestore(&phba->scsi_buf_list_put_lock, pflag);
+ list_for_each_entry(lpfc_cmd, &phba->lpfc_scsi_buf_list_get,
+ list) {
+ if (lpfc_test_rrq_active(
+ phba, ndlp, lpfc_cmd->cur_iocbq.sli4_lxritag))
+ continue;
+ list_del(&lpfc_cmd->list);
+ found = 1;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&phba->scsi_buf_list_get_lock, gflag);
if (!found)
return NULL;
- else
- return lpfc_cmd;
+ return lpfc_cmd;
}
/**
* lpfc_get_scsi_buf - Get a scsi buffer from lpfc_scsi_buf_list of the HBA
@@ -1185,10 +1205,14 @@
{
unsigned long iflag = 0;
- spin_lock_irqsave(&phba->scsi_buf_list_lock, iflag);
+ psb->seg_cnt = 0;
+ psb->nonsg_phys = 0;
+ psb->prot_seg_cnt = 0;
+
+ spin_lock_irqsave(&phba->scsi_buf_list_put_lock, iflag);
psb->pCmd = NULL;
- list_add_tail(&psb->list, &phba->lpfc_scsi_buf_list);
- spin_unlock_irqrestore(&phba->scsi_buf_list_lock, iflag);
+ list_add_tail(&psb->list, &phba->lpfc_scsi_buf_list_put);
+ spin_unlock_irqrestore(&phba->scsi_buf_list_put_lock, iflag);
}
/**
@@ -1206,6 +1230,10 @@
{
unsigned long iflag = 0;
+ psb->seg_cnt = 0;
+ psb->nonsg_phys = 0;
+ psb->prot_seg_cnt = 0;
+
if (psb->exch_busy) {
spin_lock_irqsave(&phba->sli4_hba.abts_scsi_buf_list_lock,
iflag);
@@ -1215,11 +1243,10 @@
spin_unlock_irqrestore(&phba->sli4_hba.abts_scsi_buf_list_lock,
iflag);
} else {
-
- spin_lock_irqsave(&phba->scsi_buf_list_lock, iflag);
psb->pCmd = NULL;
- list_add_tail(&psb->list, &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_add_tail(&psb->list, &phba->lpfc_scsi_buf_list_put);
+ spin_unlock_irqrestore(&phba->scsi_buf_list_put_lock, iflag);
}
}