On Wed, Feb 5, 2020 at 2:39 PM Kristen Carlson Accardi <kristen@xxxxxxxxxxxxxxx> wrote: > > At boot time, find all the function sections that have separate .text > sections, shuffle them, and then copy them to new locations. Adjust > any relocations accordingly. > > + sort(base, num_syms, sizeof(int), kallsyms_cmp, kallsyms_swp); Hah, here's a huge bottleneck. Unless you are severely memory-constrained, never do a sort with an expensive swap function like this. Instead allocate an array of indices that starts out as [0, 1, 2, ...]. Sort *that* where the swap function just swaps the indices. Then use the sorted list of indices to permute the actual data. The result is exactly one expensive swap per item instead of one expensive swap per swap. --Andy
