Re: [PATCH v10 1/7] x86/tsc: remove tsc_disabled flag

From: Pavel Tatashin
Date: Tue Jun 19 2018 - 13:51:40 EST


> > tsc_disabled is set when notsc is passed as kernel parameter. The reason we
> > have notsc is to avoid timing problems on multi-socket systems. We already
> > have a mechanism, however, to detect and resolve these issues by invoking
> > tsc unstable path. Thus, make notsc to behave the same as tsc=unstable.
>
> notsc also excludes TSC from being used at all, while with your change its
> suddenly used in sched_clock().

Hi Thomas,

Thank you for the review. I will reword the patch comment. Currently,
at the end it says: "Thus, make notsc to behave the same as
tsc=unstable." To emphasize this, I will change the patch title to
this:

x86/tsc: redefine notsc to behave as tsc=unstable

And in the comment I will mention that as a consequence of this change
tsc is going to be used by sched_clock() when notsc is provided.

Thank you,
Pavel