On 19 November 2013 15:11, Morten Rasmussen morten.rasmussen@arm.com wrote:
On Tue, Nov 19, 2013 at 01:27:14PM +0000, Vincent Guittot wrote:
On 19 November 2013 14:19, Alex Shi alex.shi@linaro.org wrote:
On 11/19/2013 08:45 PM, Morten Rasmussen wrote:
On Tue, Nov 19, 2013 at 11:46:19AM +0000, Alex Shi wrote:
Since arm system rarely has much tasks running in system. this removing
Could you elaborate on the effect of this change?
I don't think the assumption that ARM systems rarely have many tasks running is generally valid. Smartphones do occasionally use all available cpus and ARM systems are used in many other segments.
I only has a panda board in hands, and don't know which benchmark are good for the testing. The key of this patch effect is testing. Anyone like to give a hand on this?
AFAIK, there are no theory can prove which decay is better (but obviously, community prefer to sched_avg, since it was added when cpu_load already existed.)
sched_avg is better because it can't miss any load whereas cpu_load average can miss tasks that don't wakeup synchronously to tick
But cpu_load[] is already based on the sched_avg load?
Ah you're right that we have mode the cpu_load on load_avg. Nevertheless, the cpu_load is based on the instant value of the load_avg at the tick and not the integration of the value between tick which still make it possible to miss some activity
Vincent
Morten