On 9/20/23 00:11, Dave Hansen wrote: > On 9/18/23 18:11, Yin Fengwei wrote: >>> I will find a test machine to measure the performance difference of these two >>> versions by using xfs + will-it-scale. Will keep you guys updated. >> I'd like to move this bug fixing forward. Based on the test result here: >> https://lore.kernel.org/linux-mm/124631ab-eb4c-6584-12d4-f3c91e69c873@xxxxxxxxx/ >> There is very small performance delta between your version and Dave's. >> >> What do you think if we propose to merge Dave's version? Or do I need collect >> more data? Thanks. > > I honestly don't feel that strongly about my version versus Matthew's. > I like mine, but I'll happily ack either approach. > > The thing I care about the most is getting the bug fixed ... quickly. :) Same in my side. Regarding the performance delta is very small, I thought we should follow the commit message of 6b28baca9b1f0d4a42b865da7a05b1c81424bd5c: The invert is done by pte/pmd_modify and pfn/pmd/pud_pte for PROTNONE and pte/pmd/pud_pfn undo it. This assume that no code path touches the PFN part of a PTE directly without using these primitives. Regards Yin, Fengwei
