Comment 4 for bug 746860

All right. Seems that there were two bugs with similar symptoms. The one from comment #3 is already fixed, but a new bisect revealed the following root cause for the current regression:

dcd989cb73ab0f7b722d64ab6516f101d9f43f88 is the first bad commit
commit dcd989cb73ab0f7b722d64ab6516f101d9f43f88
Author: Tejun Heo <email address hidden>
Date: Tue Jun 29 10:07:14 2010 +0200

   workqueue: implement several utility APIs

   Implement the following utility APIs.

    workqueue_set_max_active() : adjust max_active of a wq
    workqueue_congested() : test whether a wq is contested
    work_cpu() : determine the last / current cpu of a work
    work_busy() : query whether a work is busy

   * Anton Blanchard fixed missing ret initialization in work_busy().

   Signed-off-by: Tejun Heo <email address hidden>
   Cc: Anton Blanchard <email address hidden>

:040000 040000 8b7443c650f0af36f1deba560586a91f6a88abcc
065589a95857a2fb73b94dc242c50ba558179a2a M include
:040000 040000 84ca2de78af16483fa60a423f4f2d6eee0279eed
27487850f11a1e7ee9e4eaac54fd88f16d420d47 M kernel