[..] > > I'm not trying to delay this patch - I fully believe in supporting > zswap for larger pages (both mTHP and THP - whatever the memory > reclaim subsystem throws at us). > > But we need to get to the bottom of this :) These are very suspicious > and concerning data. If this is something urgent, I can live with a > gate to enable/disable this, but I'd much prefer we understand what's > going on here. Agreed. I don't think merging this support is urgent, so I think we should better understand what is happening here. If there is a problem with how we charge compressed memory today (temporary double charges), we need to sort this out before the the mTHP support, as it will only make things worse. I have to admit I didn't take a deep look at the discussion and data, so there may be other problems that I didn't notice. It seems to me like Kanchana is doing more debugging to understand what is happening, so that's great! As for the patches, we should sort out the impact on a higher level before discussing implementation details. From a quick look though it seems like the first patch can be dropped after Usama's patches that remove the same-filled handling from zswap land, and the last two patches can be squashed.
