Re: [RFC PATCH for 4.17 10/21] cpu_opv: Provide cpu_opv system call (v6)

2018-03-28 Thread Mathieu Desnoyers
- On Mar 28, 2018, at 11:22 AM, Peter Zijlstra pet...@infradead.org wrote: > On Tue, Mar 27, 2018 at 12:05:31PM -0400, Mathieu Desnoyers wrote: > >> 1) Allow algorithms to perform per-cpu data migration without relying on >>sched_setaffinity() >> >> The use-cases are migrating memory bet

Re: [RFC PATCH for 4.17 10/21] cpu_opv: Provide cpu_opv system call (v6)

2018-03-28 Thread Peter Zijlstra
On Tue, Mar 27, 2018 at 12:05:31PM -0400, Mathieu Desnoyers wrote: > 1) Allow algorithms to perform per-cpu data migration without relying on >sched_setaffinity() > > The use-cases are migrating memory between per-cpu memory free-lists, or > stealing tasks from other per-cpu work queues: each

[RFC PATCH for 4.17 10/21] cpu_opv: Provide cpu_opv system call (v6)

2018-03-27 Thread Mathieu Desnoyers
The cpu_opv system call executes a vector of operations on behalf of user-space on a specific CPU with preemption disabled. It is inspired by readv() and writev() system calls which take a "struct iovec" array as argument. The operations available are: comparison, memcpy, add, or, and, xor, left s