On Thu, Aug 27, 2026 at 05:19:30PM +0200, David Hildenbrand (Arm) wrote: > On 8/27/26 13:18, Lorenzo Stoakes (ARM) wrote: > > On Thu, Aug 27, 2026 at 12:16:32PM +0100, Lorenzo Stoakes (ARM) wrote: > >> So actually you're increasing by a cacheline and increasing the VMA size by > >> 64 bytes, i.e. 1/3, which is unacceptable obviously. > >> > >> Maybe there's something that can be done with: > >> > >> /* forced alignments: 1 */ > >> > >> Perhaps? But that looks potentially ugly. > >> > > > > I say elsewhere (or think I do) but to highlight - I think probably we > > could fix > > this by putting the flags in the low bits of vm_uffd_state.ctx? > > if that's possible that would be clearly preferable memory-wise.
This gives only 4 bits and makes this completely not extendable. So I think I'll drop this for now and wait until VMA grows another cache line or until having per-VMA uffd state rather than a pointer to per-fd context is a must. > -- > Cheers, > > David -- Sincerely yours, Mike.
