[bug report] NVMe/IB: reset_controller need more than 1min

[Yi Zhang]

Hi Sagi/Max

Changing the value to 10 or 15 fixed the timeout issue.
And the reset operation still needs more than 12s on my environment, I
also tried disabling the pi_enable, the reset operation will be back
to 3s, so seems the added 9s was due to the PI enabled code path.

On Mon, Feb 14, 2022 at 8:12 PM Max Gurtovoy <mgurtovoy at nvidia.com> wrote:
>
>
> On 2/14/2022 1:32 PM, Sagi Grimberg wrote:
> >
> >> Hi Sagi/Max
> >> Here are more findings with the bisect:
> >>
> >> The time for reset operation changed from 3s[1] to 12s[2] after
> >> commit[3], and after commit[4], the reset operation timeout at the
> >> second reset[5], let me know if you need any testing for it, thanks.
> >
> > Does this at least eliminate the timeout?
> > --
> > diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> > index a162f6c6da6e..60e415078893 100644
> > --- a/drivers/nvme/host/nvme.h
> > +++ b/drivers/nvme/host/nvme.h
> > @@ -25,7 +25,7 @@ extern unsigned int nvme_io_timeout;
> >  extern unsigned int admin_timeout;
> >  #define NVME_ADMIN_TIMEOUT     (admin_timeout * HZ)
> >
> > -#define NVME_DEFAULT_KATO      5
> > +#define NVME_DEFAULT_KATO      10
> >
> >  #ifdef CONFIG_ARCH_NO_SG_CHAIN
> >  #define  NVME_INLINE_SG_CNT  0
> > --
> >
> or for the initial test you can use --keep-alive-tmo=<10 or 15> flag in
> the connect command
>
> >>
> >> [1]
> >> # time nvme reset /dev/nvme0
> >>
> >> real 0m3.049s
> >> user 0m0.000s
> >> sys 0m0.006s
> >> [2]
> >> # time nvme reset /dev/nvme0
> >>
> >> real 0m12.498s
> >> user 0m0.000s
> >> sys 0m0.006s
> >> [3]
> >> commit 5ec5d3bddc6b912b7de9e3eb6c1f2397faeca2bc (HEAD)
> >> Author: Max Gurtovoy <maxg at mellanox.com>
> >> Date:   Tue May 19 17:05:56 2020 +0300
> >>
> >>      nvme-rdma: add metadata/T10-PI support
> >>
> >> [4]
> >> commit a70b81bd4d9d2d6c05cfe6ef2a10bccc2e04357a (HEAD)
> >> Author: Hannes Reinecke <hare at suse.de>
> >> Date:   Fri Apr 16 13:46:20 2021 +0200
> >>
> >>      nvme: sanitize KATO setting-
> >
> > This change effectively changed the keep-alive timeout
> > from 15 to 5 and modified the host to send keepalives every
> > 2.5 seconds instead of 5.
> >
> > I guess that in combination that now it takes longer to
> > create and delete rdma resources (either qps or mrs)
> > it starts to timeout in setups where there are a lot of
> > queues.
>


-- 
Best Regards,
  Yi Zhang