Re: Race to power off harming SATA SSDs

[Henrique de Moraes Holschuh <hmh@hmh.eng.br>]

On Mon, 10 Apr 2017, James Bottomley wrote:
> On Tue, 2017-04-11 at 08:52 +0900, Tejun Heo wrote:
> [...]
> > > Any comments?  Any clues on how to make the delay "smarter" to 
> > > trigger only once during platform shutdown, but still trigger per
> > > -device when doing per-device hotswapping ?
> > 
> > So, if this is actually an issue, sure, we can try to work around;
> > however, can we first confirm that this has any other consequences
> > than a SMART counter being bumped up?  I'm not sure how meaningful
> > that is in itself.
> 
> Seconded; especially as the proposed patch is way too invasive: we run

It is a proof of concept thing.  It even says so in the patch commit
log, and in the cover text.

I don't want an one second delay per device.  I never proposed that,
either.  In fact, I *specifically* asked for something else in the
paragraph you quoted.

I would much prefer an one- or two-seconds delay per platform *power
off*.  And that's for platforms that do ACPI-like heavy-duty S3/S4/S5
like x86/x86-64.  Opportunistic high-frequency suspend on mobile likely
requires no such handling.

The per-device delay would be needed only for hotplug removal (device
delete), and that's just because some hardware powers down bays (like
older thinkpads with ATA-compatible bays, and some industrial systems).

-- 
  Henrique Holschuh