[Removed Suresh and Venki from discussion, they switched their companies probably]
On 7 January 2013 20:34, Tejun Heo firstname.lastname@example.org wrote:
The latter part "not using idle cpu just for processing work" does apply to homogeneous systems too but as I wrote earlier work items don't spontaneously happen on an idle core. Something, including timer, needs to kick it. So, by definition, a CPU already isn't idle when a work item starts execution on it. What am I missing here?
We are talking about a core being idle from schedulers perspective :)
I have another idea that we can try:
With this we would not break any existing code and can try to migrate old users to this new infrastructure (atleast the ones which are rearming works from their work_handlers). What do you say?
Yeah, this could be a better solution, I think. Plus, it's not like finding the optimal cpu is free.
Thanks for the first part (When i shared this idea with Vincent and Amit, i wasn't sure at all about the feedback i will get from you and others, but i am very happy now :) ).
I couldn't understand the second part. We still need to search for a free cpu for this new routine. And the implementation would almost be same as the implementation of queue_work() in my initial patch
To take care of the cache locality issue, we can pass an argument to this routine, that can provide
- the mask of cpus to schedule this work on OR
- Sched Level (SD_LEVEL) of cpus to run it.
Let's start simple for now. If we really need it, we can always add more later.
:) Agreed. But i liked the idea from steven, we can have two routines: queue_work_on_any_cpu() and queue_work_on_cpus()