RE: [PATCH] rcu: Narrow early boot window of illegal synchronous grace periods

Zheng, Lv
2017-01-16T01:57:30Z

Hi,

> From: Borislav Petkov [mailto:bp@alien8.de]
> Subject: Re: [PATCH] rcu: Narrow early boot window of illegal synchronous grace periods
>
> On Sat, Jan 14, 2017 at 01:27:40PM +0100, Rafael J. Wysocki wrote:
> > OK, so this fixes the problem with synchronize_rcu_expedited() in
> > acpi_os_map_cleanup(), right?
>
> Yeah.
>
> > I wonder if the ACPI-specific fix is still needed, then?
>
> It is not strictly necessary. If you still think it would be better to
> have it regardless, you could pick it up. I.e., making ACPI more robust,
> yadda yadda.
>
> I dunno, though, perhaps it is only complicating the code unnecessarily
> and then can be safely ignored with a mental note for future freezes.

Glad to see it fixed inside of the API provider.

IMO, ACPI fix is unnecessary as ACPI is just a user of the RCU APIs.
And it's pointless to add special checks in the user side in order to use one of them.

Thanks and best regards
Lv

>
> --
> Regards/Gruss,
> Boris.
>
> Good mailing practices for 400: avoid top-posting and trim the reply.