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We don't use 1GB pages in the direct map today, and likely won't for some time. They aren't supported on all amd64 CPUs so if we decided we were interested in d

by mlarkin 12y ago

We don't use 1GB pages in the direct map today, and likely won't for some time. They aren't supported on all amd64 CPUs so if we decided we were interested in doing that, we'd need two types of direct map layouts, one to support CPUs that had 1GB page support and one that didn't. That seems like an awful lot of complexity for questionable gain. edit: ... and if we did decide, in the future, to take advantage of 1GB page support in the direct map, I'd probably just break out the kernel area separately and continue to map it with 2MB pages.

feld 12y ago
Thanks for the reply. There's currently no support for 1GB pages in FreeBSD but someone provided a patch set that does it and has considerably improved performance for their network appliance workload. It needs to be reworked a bit before being merged, but I hope it will happen before 11-RELEASE.
- ketralnis 12y ago
  > There's currently no support for 1GB pages in FreeBSD but someone provided a patch set that does it Probably others, but some of the discussion: https://lists.freebsd.org/pipermail/freebsd-hackers/2014-November/046449.html https://lists.freebsd.org/pipermail/freebsd-hackers/2014-Nov...