On Thu, 29 Jun 2017, Madhavan Srinivasan wrote:
> On Thursday 29 June 2017 01:11 AM, Thomas Gleixner wrote:
> Idea is to handle multiple event session for a given core and
> yes, my bad, current implementation is racy/broken.
> But an alternate approach is to have a per-core mutex and
> per-core ref count to handle this.
>
> event_init path:
> per-core mutex lock
> if ( per-core[refcount] == 0) {
> rc = opal call to start the engine;
> if (rc on failure) {
> per-core mutex unlock;
> log error info;
> return error;
> }
> }
> increment the per-core[refcount];
> per-core mutex unlock;
>
>
> event_destroy path:
> per-core mutex lock
> decrement the per-core[refcount];
> if ( per-core[refcount] == 0) {
> rc = opal call to stop the engine;
> if (rc on failure) {
> per-core mutex unlock;
> log the failure;
> return error;
> }
> } else if ( per-core[refcount] < 0) {
> WARN()
> per-core[refcount] = 0;
> }
> per-core mutext unlock;
Yes, that works and looks about right.
Thanks,
tglx
