On 3/10/20 11:20 PM, Minchan Kim wrote: > On Thu, Mar 05, 2020 at 07:15:10PM +0100, Vlastimil Babka wrote: >> On 3/2/20 8:36 PM, Minchan Kim wrote: >> > There is usecase that System Management Software(SMS) want to give >> > a memory hint like MADV_[COLD|PAGEEOUT] to other processes and >> > in the case of Android, it is the ActivityManagerService. >> > >> > It's similar in spirit to madvise(MADV_WONTNEED), but the information >> >> You mean MADV_DONTNEED? > > Mean to DONT_NEED's future version. What's that exactly? >> >> > required to make the reclaim decision is not known to the app. >> >> This seems to be mixing up the differences between MADV_DONTNEED and >> COLD/PAGEOUT and self-imposed vs external memory hints? > > Sorry, I don't understand what you want here. You say that process_madvise(MADV_[COLD|PAGEEOUT]) is similar to madvise(MADV_WONTNEED) but the difference is that the information required to make the reclaim decision is not known to the app. I see two differences. One is madvise vs process_madvise, which is explained by "reclaim decision is not known to the app." The other is MADV_WONTNEED vs MADV_[COLD|PAGEEOUT], which is... I'm not sure until you say what's "DONT_NEED's future version" :D Anyway I assume this part is from the versions where the new COLD and PAGEOUT flags were introduced together with external memory hinting API?
