Stupid script... Cc'ing Oleg.
On Mon, 2014-04-14 at 16:57 -0700, Davidlohr Bueso wrote:
> For single threaded workloads, we can avoid flushing
> and iterating through the entire list of tasks, making
> the whole function a lot faster, requiring only a single
> atomic read for the mm_users.
>
> Suggested-by: Oleg Nesterov <oleg@xxxxxxxxxx>
> Signed-off-by: Davidlohr Bueso <davidlohr@xxxxxx>
> ---
> mm/vmacache.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/mm/vmacache.c b/mm/vmacache.c
> index e167da2..61c38ae 100644
> --- a/mm/vmacache.c
> +++ b/mm/vmacache.c
> @@ -17,6 +17,16 @@ void vmacache_flush_all(struct mm_struct *mm)
> {
> struct task_struct *g, *p;
>
> + /*
> + * Single threaded tasks need not iterate the entire
> + * list of process. We can avoid the flushing as well
> + * since the mm's seqnum was increased and don't have
> + * to worry about other threads' seqnum. Current's
> + * flush will occur upon the next lookup.
> + */
> + if (atomic_read(&mm->mm_users) == 1)
> + return;
> +
> rcu_read_lock();
> for_each_process_thread(g, p) {
> /*
--
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