On Thu, Jan 05, 2017 at 09:16:02AM +0000, Steven Hartland wrote: > Given the use of the number of CPU's for sizing would this play nice > with hot plug CPU's? > > Regards > Steve
Not without some work. I don't think it would be a major obstacle to adding hot-plug CPU support on at least 64-bit systems though. > > On 05/01/2017 01:44, Mark Johnston wrote: > > Author: markj > > Date: Thu Jan 5 01:44:12 2017 > > New Revision: 311346 > > URL: https://svnweb.freebsd.org/changeset/base/311346 > > > > Log: > > Add a small allocator for exec_map entries. > > > > Upon each execve, we allocate a KVA range for use in copying data to the > > new image. Pages must be faulted into the range, and when the range is > > freed, the backing pages are freed and their mappings are destroyed. This > > is a lot of needless overhead, and the exec_map management becomes a > > bottleneck when many CPUs are executing execve concurrently. Moreover, > > the > > number of available ranges is fixed at 16, which is insufficient on large > > systems and potentially excessive on 32-bit systems. > > > > The new allocator reduces overhead by making exec_map allocations > > persistent. When a range is freed, pages backing the range are marked > > clean > > and made easy to reclaim. With this change, the exec_map is sized based > > on > > the number of CPUs. _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
