On 06/04/2015 11:32 AM, Viresh Kumar wrote:
On 04-06-15, 11:08, Preeti U Murthy wrote:
I don't see why we need the check on policy->governor->initialized because we call cdata->init() and cdata->exit(), *only* when the first and last references to the governor are being made respectively (filtered by dbs_data->usage_count), which is precisely what the initialized flag checks. So passing policy->governor->initialized seems to be redundant? And this is the case for both gov_per_policy and otherwise.
That's the case only for !gov_per_policy.
In case of gov_per_policy, the same governor is used by multiple policies but with different dbs_data objects. And in this case INIT will be called only once for a dbs_data and so usage count will be max 1 at any time. But we want to register the notifiers for a governor only once and so we need this extra check.
policy->governor->initialized is set to 1 when the governor is initialized for the first policy. For all others it is incremented to other values.
Ok I see. The patch looks good to me then.
Reviewed-by: Preeti U Murthy preeti@linux.vnet.ibm.com