On Fri, 13 Nov 2020 17:09:37 -0800 Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > > > > Seems to me that the ability to reap another process's memory is a > > > > generally useful one, and that it should not be tied to delivering a > > > > signal in this fashion. > > > > > > > > And we do have the new process_madvise(MADV_PAGEOUT). It may need a > > > > few changes and tweaks, but can't that be used to solve this problem? > > > > > > Thank you for the feedback, Andrew. process_madvise(MADV_DONTNEED) was > > > one of the options recently discussed in > > > https://lore.kernel.org/linux-api/CAJuCfpGz1kPM3G1gZH+09Z7aoWKg05QSAMMisJ7H5MdmRrRhNQ@xxxxxxxxxxxxxx > > > . The thread describes some of the issues with that approach but if we > > > limit it to processes with pending SIGKILL only then I think that > > > would be doable. > > > > Why would it be necessary to read /proc/pid/maps? I'd have thought > > that a starting effort would be > > > > madvise((void *)0, (void *)-1, MADV_PAGEOUT) > > > > (after translation into process_madvise() speak). Which is equivalent > > to the proposed process_madvise(MADV_DONTNEED_MM)? > > Yep, this is very similar to option #3 in > https://lore.kernel.org/linux-api/CAJuCfpGz1kPM3G1gZH+09Z7aoWKg05QSAMMisJ7H5MdmRrRhNQ@xxxxxxxxxxxxxx > and I actually have a tested prototype for that. Why is the `vector=NULL' needed? Can't `vector' point at a single iovec which spans the whole address range? > If that's the > preferred method then I can post it quite quickly. I assume you've tested that prototype. How did its usefulness compare with this SIGKILL-based approach?
