On Mon, Feb 6, 2023 at 11:33 PM Jaewon Kim <jaewon31.kim@xxxxxxxxxxx> wrote: > >I don't mean to discourage you, especially after all the effort here. > > > >Do you think evaluating the before and after impact to buffer usage > > > >(not just allocation) would be doable in the near term? > > > > Hello sorry but I don't have expertise on iommu. Actually I'm also wondering > all IOMMU can use order 4 free pages, if they are allocated. I am not sure > but I remember I heard order 9 (2MB) could be used, but I don't know about order 8 4. > > I guess IOMMU mmap also be same patern like we expect. I mean if order 4 is > prepared it could be faster like 1 to 4 times. But it, I think, should NOT be > that much slow even though the entire free memory is prepared as order 0 pages. > > > > > > >If you don't think so, given the benefit to allocation under pressure > > > >is large (and I don't mean to give you hurdles to jump), I'm willing > > > >to ack your change to get it merged, but if we later see performance > > > >trouble, I'll be quick to advocate for reverting it. Is that ok? > > > > Yes sure. I also want to know if it is. Ok. Please resend your latest patch and I'll go ahead and ack it and we'll watch. Thanks again for your efforts here! -john
