Re: [PATCH 0/8] workqueue: advance concurrency management

[Lai Jiangshan]

On Sat, Apr 20, 2013 at 2:11 AM, Tejun Heo <tj@xxxxxxxxxx> wrote:
> Hey,
>
> On Fri, Apr 19, 2013 at 06:10:57AM +0800, Lai Jiangshan wrote:
>> Ping.
>
> Sorry, I've been at collab summit / lsf.  Plus, it's a bit too late
> for for-3.10 anyway.  Anyways, after glancing over it, here are my
> preliminary thoughts.  The first one looks good but I'm not sure about
> dropping nr_running adjustment.  The only real benefit coming from
> that is dropping a sched callback and if there's any performance /
> overhead impact, I'm afraid it's gonna be negative.  There are actual
> benefits in using as few tasks as possible -

waking_up() callback doesn't win too much in this.


> the cache footprint gets smaller,

cache footprint also be reduced in different way in the patchset.
and memory atomic operations are reduced.

> so unless there's a clear indication that the suggested

Only simple.
and remove the optimization from rare cases.

> behavior is better in some way, I'm not sure what we're buying with
> the proposed changes.
>
> Thanks.
>
> --
> tejun
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