Re: [PATCH 3/3] x86/tsc: don't check for random warps if using direct sync

[Thomas Gleixner]

On Mon, Aug 08 2022 at 16:39, Muhammad Usama Anjum wrote:
> There's some overhead in writing and reading MSR_IA32_TSC. We try to
> account for it. But sometimes overhead gets under or over estimated.
> When we retry syncing, it sees the clock "go backwards". Hence,
> ignore random wrap if using direct sync.

This is just wrong. If the sync test can observe clock going backwards
then it can be observed during runtime too. Preventing that is the whole
point of the TSC sync exercise.

Thanks,

        tglx