Re: Realtime threads delayed due to kcompactd0

[Alexander Krabler <Alexander.Krabler@kuka.com>]

On Fri, Aug 1, 2025 at 9:27 PM Frank van der Linden <fvdl@google.com> wrote:
> Another idea is to minimize the time that a migration PTE is in place
> for an mlocked page, Hugh (cc-ed) mentioned this in an offline
> discussion. E.g. skip any mlocked pages in the first pass, and just
> add them to a list. Then, do that list separately, but do them one by
> one. There is somewhat similar logic in migrate_pages_sync for pages
> that might need extra work / locking.

Another idea might be, that the blocked task migrates the page it is blocked on
by itself, removes the migration PTE and continues?
Doing the work itself instead of waiting for another thread to do the work.
Would that be possible?

This would solve the priority inversion problem and should be way more
deterministic than the current situation.

Alexander

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