On (23/05/08 09:00), Nhat Pham wrote: > > The deeper bug here is that zs_map_object() tries to add the page to > > the LRU list while the shrinker has it isolated for reclaim. This is > > way too sutble and error prone. Even if it worked now, it'll cause > > corruption issues down the line. > > > > For example, Nhat is adding a secondary entry point to reclaim. > > Reclaim expects that a page that's on the LRU is also on the fullness > > list, so this would lead to a double remove_zspage() and BUG_ON(). > > > > This patch doesn't just fix the crash, it eliminates the deeper LRU > > isolation issue and makes the code more robust and simple. > > I agree. IMO, less unnecessary concurrent interaction is always a > win for developers' and maintainers' cognitive load. Thanks for all the explanations. > As a side benefit - this also gets rid of the inelegant check > (mm == ZS_MM_WO). The fact that we had to include a > a multi-paragraph explanation for a 3-line piece of code > should have been a red flag. Minchan had some strong opinion on that, so we need to hear from him before we decide how do we fix it.
