Re: Race to power off harming SATA SSDs

Henrique de Moraes Holschuh
2017-04-11T02:02:41Z

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