On Wed, May 18, 2022 at 02:14:28PM +0200, Michal Hocko wrote: > On Wed 18-05-22 07:40:30, CGEL wrote: > [...] > > 2. process_madvise is still a kind of madvise. processs_madvise from > > another process overrides the intention of origin app code ifself that > > also calls madvise, which is unrecoverable. For example, if a process "A" > > which madvises just one part of VMAs (not all) as MERGEABLE run on the OS > > already, meanwhile, if another process which doesn't know the information > > of "A" 's MERGEABLE areas, then call process_madvise to advise all VMAs of > > "A" as MERGEABLE, the original MERGEABLE information of "A" calling madivse > > is erasured permanently. > > I do not really follow. How is this any different from an external > process modifying the process wide policy via the proc or any other > interface? In this patch, you can see that we didn't modify the flag of any VMA of the target process, which is different from process_madvise. So it is easy to keep the original MERGEABLE information of the target process when we turn back to the default state from the state "always". > -- > Michal Hocko > SUSE Labs
