workqueue: could work->func be reused for private data by introducing per-wq default function?

[Gao Xiang]

Hi Tejun Heo, Lai Jiangshan,

    I don't know whether the related topic was discussed or not (or 
it's actually an insane proposal :( )

    It seems that the most of workqueues INIT_WORK by a default handle 
function.

    So could we use a per-workqueue default handle function for these 
workqueues, and leave an extra private data field for each work_struct?

    There are so many work_structs that we could reuse the func field 
for the other uses.

    Is it acceptable? I haven't dived into the workqueue implementation 
yet, but it seems not straight-forward for find_worker_executing_work, 
etc. at a glance.


    Thanks,

Gao Xiang