On Thu 19-05-22 06:35:03, CGEL wrote: > 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". This means that /proc/<pid>/smaps doesn't show the real state, right? -- Michal Hocko SUSE Labs
