Thread (21 messages) 21 messages, 4 authors, 2021-07-13
STALE1781d
Revisions (4)
  1. v1 [diff vs current]
  2. v2 current
  3. v3 [diff vs current]
  4. v4 [diff vs current]

[PATCH v2 11/14] scsi: lpfc: Use irq_set_affinity

From: Nitesh Narayan Lal <hidden>
Date: 2021-06-29 15:30:43
Also in: intel-wired-lan, linux-api, linux-pci, lkml, netdev
Subsystem: emulex/broadcom lpfc fc/fcoe scsi driver, scsi subsystem, the rest · Maintainers: Justin Tee, Paul Ely, "James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds

The driver uses irq_set_affinity_hint to set the affinity for the lpfc
interrupts to a mask corresponding to the local NUMA node to avoid
performance overhead on AMD architectures.

However, irq_set_affinity_hint() setting the affinity is an undocumented
side effect that this function also sets the affinity under the hood.
To remove this side effect irq_set_affinity_hint() has been marked as
deprecated and new interfaces have been introduced.

Also, as per the commit dcaa21367938 ("scsi: lpfc: Change default IRQ model
on AMD architectures"):
"On AMD architecture, revert the irq allocation to the normal style
(non-managed) and then use irq_set_affinity_hint() to set the cpu affinity
and disable user-space rebalancing."
we don't really need to set the affinity_hint as user-space rebalancing for
the lpfc interrupts is not desired.

Hence, replace the irq_set_affinity_hint() with irq_set_affinity() which
only applies the affinity for the interrupts.

Signed-off-by: Nitesh Narayan Lal <redacted>
---
 drivers/scsi/lpfc/lpfc_init.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 5f018d02bf56..d6e48414018d 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -11360,7 +11360,7 @@ lpfc_irq_set_aff(struct lpfc_hba_eq_hdl *eqhdl, unsigned int cpu)
 	cpumask_clear(&eqhdl->aff_mask);
 	cpumask_set_cpu(cpu, &eqhdl->aff_mask);
 	irq_set_status_flags(eqhdl->irq, IRQ_NO_BALANCING);
-	irq_set_affinity_hint(eqhdl->irq, &eqhdl->aff_mask);
+	irq_set_affinity(eqhdl->irq, &eqhdl->aff_mask);
 }
 
 /**
@@ -11649,7 +11649,6 @@ lpfc_sli4_enable_msix(struct lpfc_hba *phba)
 	for (--index; index >= 0; index--) {
 		eqhdl = lpfc_get_eq_hdl(index);
 		lpfc_irq_clear_aff(eqhdl);
-		irq_set_affinity_hint(eqhdl->irq, NULL);
 		free_irq(eqhdl->irq, eqhdl);
 	}
 
@@ -11810,7 +11809,6 @@ lpfc_sli4_disable_intr(struct lpfc_hba *phba)
 		for (index = 0; index < phba->cfg_irq_chann; index++) {
 			eqhdl = lpfc_get_eq_hdl(index);
 			lpfc_irq_clear_aff(eqhdl);
-			irq_set_affinity_hint(eqhdl->irq, NULL);
 			free_irq(eqhdl->irq, eqhdl);
 		}
 	} else {
-- 
2.27.0
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