Messages in this thread | | | Date | Thu, 30 Jan 2020 13:02:53 +0100 | From | Michal Hocko <> | Subject | Re: [v2 PATCH] move_pages.2: Returning positive value is a new error case |
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On Thu 30-01-20 10:06:28, Vlastimil Babka wrote: > On 1/29/20 10:48 PM, Yang Shi wrote: > > Since commit a49bd4d71637 ("mm, numa: rework do_pages_move"), > > the semantic of move_pages() has changed to return the number of > > non-migrated pages if they were result of a non-fatal reasons (usually a > > busy page). This was an unintentional change that hasn't been noticed > > except for LTP tests which checked for the documented behavior. > > > > There are two ways to go around this change. We can even get back to the > > original behavior and return -EAGAIN whenever migrate_pages is not able > > The manpage says EBUSY, not EAGAIN? And should its description be > updated too?
The idea was that we _could_ return EAGAIN from the syscall if migrate_pages > 0.
> I.e. that it's no longer returned since 4.17?
I am pretty sure this will require a deeper consideration. Do we return EIO/EINVAL? -- Michal Hocko SUSE Labs
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