On Sat, Nov 11, 2017 at 4:22 PM, <ti...@openmailbox.org> wrote: > Theo 2016-07-11 15:09:48, https://marc.info/?l=openbsd- > tech&m=146824981122013&w=2 , > https://marc.info/?l=openbsd-tech&m=146825098022380&w=2 : > > And bufs don't need it either. Have you actually cranked your buffer > > cache that high? I have test this, on sparc64 which has unlimited DMA > > reach due to the iommu. The system comes to a crawl when there are > > too many mbufs or bufs, probably due to management structures unable > > to handle the pressure. > > Theo 2016-07-11 16:16:13 , https://marc.info/?l=openbsd- > tech&m=146825379723312&w=2 : > > I was simply pointing out that massive (well above 4GB) buffer cache > > on a 64-bit DMA-reachable machine worked poorly. Likely due to data > > structures managing the memory with rather large O... > > What algorithms drive the buffer cache structure now?
If I recall Bob and Ted's undeadly posts correctly, the buffers are both in per-vnode red-black trees and a global 2Q structure to manage the total set of buffers. (How those names will be useful I don't know.) Philip Guenther
