On Fri, 2015-03-27 at 10:03 +0530, Preeti U Murthy wrote: > Hi Wanpeng > > On 03/27/2015 07:42 AM, Wanpeng Li wrote: > > Hi Preeti, > > On Thu, Mar 26, 2015 at 06:32:44PM +0530, Preeti U Murthy wrote: > >> > >> 1. An ILB CPU was chosen from the first numa domain to trigger nohz idle > >> load balancing [Given the experiment, upto 6 CPUs per core could be > >> potentially idle in this domain.] > >> > >> 2. However the ILB CPU would call load_balance() on itself before > >> initiating nohz idle load balancing. > >> > >> 3. Given cores are SMT8, the ILB CPU had enough opportunities to pull > >> tasks from its sibling cores to even out load. > >> > >> 4. Now that the ILB CPU was no longer idle, it would abort nohz idle > >> load balancing > > > > I don't see abort nohz idle load balancing when ILB CPU was no longer idle > > in nohz_idle_balance(), could you explain more in details? > > When the ILB CPU pulls load in rebalance_domains(), its idle state > is set to CPU_NOT_IDLE. > > "" > idle = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE;
Hi Preeti, The "idle" variable is a local variable to the rebalance_domains() function. In that case, that shouldn't have an affect on the idle value that gets passed to nohz_idle_balance(). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/