Re: Report long suspend times of NVMe devices (mostly firmware/device issues)

[Paul Menzel]

Dear Keith,


Thank you for your reply.

Am 22.01.2018 um 22:30 schrieb Keith Busch:
> On Mon, Jan 22, 2018 at 10:02:12PM +0100, Paul Menzel wrote:

> > Benchmarking the ACPI S3 suspend and resume times with `sleepgraph.py
> > -config config/suspend-callgraph.cfg` [1], shows that the NVMe disk SAMSUNG
> > MZVKW512HMJP-00000 in the TUXEDO Book BU1406 takes between 0.3 and 1.4
> > seconds, holding up the suspend cycle.
> >
> > The time is spent in `nvme_shutdown_ctrl()`.
> >
> > ### Linux 4.14.1-041401-generic
> >
> > > nvme @ 0000:04:00.0 {nvme} async_device (Total Suspend: 1439.299 ms Total Resume: 19.865 ms)
> >
> > ### Linux 4.15-rc9
> >
> > > nvme @ 0000:04:00.0 {nvme} async_device (Total Suspend: 362.239 ms Total Resume: 19.897 m
> > Itâd be useful, if the Linux kernel logged such issues visibly to the user,
> > so that the hardware manufacturer can be contacted to fix the device
> > (probably the firmware).
> >
> > In my opinion anything longer than 200 ms should be reported similar to [2],
> > and maybe worded like below.
> >
> > > NVMe took more than 200 ms to do suspend routine
> >
> > What do you think?
>
> The nvme spec guides toward longer times than that. I don't see the
> point of warning users about things operating within spec.

I quickly glanced over NVM Express revision 1.3 specification [1] but 
searching for *second *, I could not find something about this. Could 
you please point me to the section?

In my opinion, itâs a good thing to point users to devices holding up 
suspend.


Kind regards,

Paul


[1] https://nvmexpress.org/wp-content/uploads/NVM_Express_Revision_1.3.pdf