On Thu, Apr 12, 2018 at 12:59 PM, Mathieu Desnoyers <mathieu.desnoy...@efficios.com> wrote: > > What are your concerns about page pinning ?
Pretty much everything. It's the most complex part by far, and the vmalloc space is a limited resource on 32-bit architectures. > Do you have an alternative approach in mind ? Do everything in user space. And even if you absolutely want cpu_opv at all, why not do it in the user space *mapping* without the aliasing into kernel space? The cpu_opv approach isn't even fast. It's *really* slow if it has to do VM crap. The whole rseq thing was billed as "faster than atomics". I *guarantee* that the cpu_opv's aren't faster than atomics. Linus