On Sun, Oct 13, 2024 at 12:56 AM Shakeel Butt <shakeel.butt@xxxxxxxxx> wrote: > > On Thu, Oct 10, 2024 at 01:56:42PM GMT, Andrii Nakryiko wrote: > > To increase mm->mm_lock_seq robustness, switch it from int to long, so > > that it's a 64-bit counter on 64-bit systems and we can stop worrying > > about it wrapping around in just ~4 billion iterations. Same goes for > > VMA's matching vm_lock_seq, which is derived from mm_lock_seq. vm_lock_seq does not need to be long but for consistency I guess that makes sense. While at it, can you please change these seq counters to be unsigned? Also, did you check with pahole if the vm_area_struct layout change pushes some members into a difference cacheline or creates new gaps? > > > > I didn't use __u64 outright to keep 32-bit architectures unaffected, but > > if it seems important enough, I have nothing against using __u64. > > > > Suggested-by: Jann Horn <jannh@xxxxxxxxxx> > > Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > > Reviewed-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>
