Hi John,
Removing ioc->is_gen35_ioc condition will enable Shared host tag.
We have not tested it with older generation of controllers.
I will test it and let you know.
Thanks,
Suganath
On Wed, Apr 21, 2021 at 3:57 PM John Garry <john.garry@xxxxxxxxxx> wrote:
>
> On 21/04/2021 11:20, Suganath Prabu Subramani wrote:
> > On Tue, Apr 20, 2021 at 8:09 PM John Garry <john.garry@xxxxxxxxxx> wrote:
> >>
> >> On 02/02/2021 09:58, Sreekanth Reddy wrote:
> >>> d transport support for SAS 3.0 HBA devices */
> >>> @@ -12028,6 +12053,21 @@ _scsih_probe(struct pci_dev *pdev, const struct pci_device_id *id)
> >>> } else
> >>> ioc->hide_drives = 0;
> >>>
> >>> + shost->host_tagset = 0;
> >>> + shost->nr_hw_queues = 1;
> >>> +
> >>> + if (ioc->is_gen35_ioc && ioc->reply_queue_count > 1 &&
>
> *
>
> >>> + host_tagset_enable && ioc->smp_affinity_enable) {
> >>> +
> >>
> >> I wanted to test host_tagset_enable feature on my LSI 3008 card (I think
> >> that it uses MP25 version), but is_gen35_ioc is not set there - is there
> >> some specific reason for which we can't support on that HW rev?
> >>
> > John,
> > We want to avoid any code changes for older generation controllers as much as
> > possible. Shared host tag is a major IO path change and for older generation
> > controllers it is better not to enable such feature and support.
> > "Fix engine policy for older controller"
>
> ok, understood.
>
> But is there a change which you can share for me to test locally?
>
> In the test for enabling, above *, I just locally removed the
> ioc->is_gen35_ioc condition and it looks to work ok. Is this good
> enough, or am I possibly doing something dangerous? I'd appreciate if
> you can share something for me to try locally.
>
> Thanks,
> John
>
> >
> >>> + shost->host_tagset = 1;
> >>> + shost->nr_hw_queues =
> >>> + ioc->reply_queue_count - ioc->high_iops_queues;
> >>> +
> >>> + dev_info(&ioc->pdev->dev,
> >>> + "Max SCSIIO MPT commands: %d shared with nr_hw_queues = %d\n",
> >>> + shost->can_queue, shost->nr_hw_queues);
> >>> + }
> >>
> >> Thanks,
> >> John
>
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