On Mon, 17 Apr 2023, Zi Yan wrote: > > What do you think? If you have a better idea, I am all ears. And if you > are willing to help me review the more complicated code changes, I am > more than happy to implement it in the next version. :) Sorry, no, not me. You'll have to persuade someone else that "optimizing" truncation is a worthwhile path to pursue (and to pursue now) - I was just trying to illustrate that the current patchset didn't seem very useful. But don't throw your work away. I expect some of it can become useful later e.g. once most of the main filesystems support large folios, and the complication of CONFIG_READ_ONLY_THP_FOR_FS can be deleted. I doubt my "minimizing the number of folios" approach would be worth the effort; I think more likely that we shall settle on an intermediate folio size (between 4K and THP: maybe 64K, but not necessarily the same on all machines or all workloads) to aim for, and then maybe truncation of THP would split to those units. But it's not a job I shall get into - I'll just continue to report and try to fix what bugs I see. Hugh
