Re: [PATCHv4 2/3] mm/gup: fix omission of check on FOLL_LONGTERM in gup fast path

Cc Mike, David, who is an expert of hugetlb and thp On Fri, Jun 14, 2019 at 5:37 AM Ira Weiny wrote: > > On Thu, Jun 13, 2019 at 06:45:01PM +0800, Pingfan Liu wrote: > > FOLL_LONGTERM suggests a pin which is going to be given to hardware and > > can't move. It would truncate CMA permanently and

Re: [PATCHv4 2/3] mm/gup: fix omission of check on FOLL_LONGTERM in gup fast path

On Thu, Jun 13, 2019 at 06:45:01PM +0800, Pingfan Liu wrote: > FOLL_LONGTERM suggests a pin which is going to be given to hardware and > can't move. It would truncate CMA permanently and should be excluded. > > FOLL_LONGTERM has already been checked in the slow path, but not checked in > the fast

[PATCHv4 2/3] mm/gup: fix omission of check on FOLL_LONGTERM in gup fast path

FOLL_LONGTERM suggests a pin which is going to be given to hardware and can't move. It would truncate CMA permanently and should be excluded. FOLL_LONGTERM has already been checked in the slow path, but not checked in the fast path, which means a possible leak of CMA page to longterm pinned