Re: [PATCH 0/6] hisi_sas: Expose multiple hw queues for v3 hw as experimental

From: John Garry
Date: Fri Oct 25 2019 - 12:04:43 EST

On 24/10/2019 15:21, John Garry wrote:
This series adds support to expose multiple hw queues for SCSI mid-layer
as an experimental feature.

For now it is experimental due to known CPU hotplug issue for managed

So now we have two module parameters to enable managed interrupts for v3
hw driver:
- auto_affine_msi_experimental:
Use managed interrupts plus and manage reply map internally. Use
request tag for IPTT (apart from reserved commands).
- expose_mq_experimental
Use managed interrupts plus and expose multipe hw queues. Manage IPTT
internally with sbitmap.

Paramater auto_affine_msi_experimental shows better performance (than
expose_mq_experimental), so we need to maintain it for now to stop
complaints about performance regression (even though enabling this
parameter is unsafe).

I want to remove these module parameters ASAP.

This series also includes a change to convert the driver to use sbitmap
where possible for managing IPTT.

Hi Martin,

Can we hold off on this series until Ming has had a look?


This series is based on 5.4 + [0], even though being advertised for
topic-sas-5.4 dev branch. Sorry for send before that is merged, but I just
wanted to get these posted.


John Garry (6):
scsi: hisi_sas: Use sbitmap for IPTT management
scsi: hisi_sas: Pass scsi_cmnd pointer to hisi_sas_hw.slot_index_alloc
scsi: hisi_sas: Add bitmaps_alloc_v3_hw()
scsi: hisi_sas: Add slot_index_alloc_v3_hw() and
scsi: hisi_sas: Split interrupt_init_v3_hw()
scsi: hisi_sas: Expose multiple hw queues for v3 as experimental

drivers/scsi/hisi_sas/hisi_sas.h | 12 ++-
drivers/scsi/hisi_sas/hisi_sas_main.c | 135 ++++++++++++-------------
drivers/scsi/hisi_sas/hisi_sas_v2_hw.c | 110 +++++++++++++-------
drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 100 ++++++++++++++++--
4 files changed, 242 insertions(+), 115 deletions(-)