Re: [PATCH 1/3] sched, timer: Remove usages of ACCESS_ONCE in the scheduler

Steven Rostedt
2015-04-14T23:59:18Z

On Tue, 14 Apr 2015 16:09:44 -0700
Jason Low <jason.low2@hp.com> wrote:

> @@ -2088,7 +2088,7 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
>
> static void reset_ptenuma_scan(struct task_struct *p)
> {
> - ACCESS_ONCE(p->mm->numa_scan_seq)++;
> + WRITE_ONCE(p->mm->numa_scan_seq, READ_ONCE(p->mm->numa_scan_seq) + 1);

Is the READ_ONCE() inside the WRITE_ONCE() really necessary?

> p->mm->numa_scan_offset = 0;
> }
>

-- Steve