On Wed, 9 May 2012 11:59:17 +0300 Gleb Natapov <gleb@xxxxxxxxxx> wrote: > Hmm, yes if it is file backed it may work. Setting up qemu to use file > backed memory is one more complication while running the test though. > I haven't checked by I am not sure that MADV_DONTNEED will drop page > immediately though. It probably puts it on some list to be freed later. > Hmm actually looking at the comments it seems like this is what happens: > > /* > * Application no longer needs these pages. If the pages are dirty, > * it's OK to just throw them away. The app will be more careful about > * data it wants to keep. Be sure to free swap resources too. The > * zap_page_range call sets things up for shrink_active_list to actually > * free > * these pages later if no one else has touched them in the meantime, > * although we could add these pages to a global reuse list for > * shrink_active_list to pick up before reclaiming other pages. > */ zap_page_range() actually frees these pages, no? Virtio balloon seems to rely on this. Thanks, Takuya -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
