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authorJames Smart <jsmart2021@gmail.com>2018-09-10 20:30:45 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-21 11:27:33 +0300
commitc9debbd29918b5772be8788b9e47fbd31956fa96 (patch)
treec066f46cd8d9ba419907b962f5742398e5eefa87 /drivers
parent2d62826e4bd58417f1e1b6e64f2fcbc950a12b07 (diff)
downloadlinux-c9debbd29918b5772be8788b9e47fbd31956fa96.tar.xz
scsi: lpfc: Correct soft lockup when running mds diagnostics
[ Upstream commit 0ef01a2d95fd62bb4f536e7ce4d5e8e74b97a244 ] When running an mds diagnostic that passes frames with the switch, soft lockups are detected. The driver is in a CQE processing loop and has sufficient amount of traffic that it never exits the ring processing routine, thus the "lockup". Cap the number of elements in the work processing routine to 64 elements. This ensures that the cpu will be given up and the handler reschedule to process additional items. Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com> Signed-off-by: James Smart <james.smart@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/scsi/lpfc/lpfc_sli.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 3406586b9201..ad4f16ab7f7a 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -3485,6 +3485,7 @@ lpfc_sli_handle_slow_ring_event_s4(struct lpfc_hba *phba,
struct hbq_dmabuf *dmabuf;
struct lpfc_cq_event *cq_event;
unsigned long iflag;
+ int count = 0;
spin_lock_irqsave(&phba->hbalock, iflag);
phba->hba_flag &= ~HBA_SP_QUEUE_EVT;
@@ -3506,16 +3507,22 @@ lpfc_sli_handle_slow_ring_event_s4(struct lpfc_hba *phba,
if (irspiocbq)
lpfc_sli_sp_handle_rspiocb(phba, pring,
irspiocbq);
+ count++;
break;
case CQE_CODE_RECEIVE:
case CQE_CODE_RECEIVE_V1:
dmabuf = container_of(cq_event, struct hbq_dmabuf,
cq_event);
lpfc_sli4_handle_received_buffer(phba, dmabuf);
+ count++;
break;
default:
break;
}
+
+ /* Limit the number of events to 64 to avoid soft lockups */
+ if (count == 64)
+ break;
}
}