Hi Peter, The point is we call use it as bellow, show_state_filter(TASK_RUNNING); because TASK_RUNNING is 0, that will dump all tasks.
Under some circumstance, we need this to dump only tasks in TASK_RUNNING state. Thanks Yafang 2017-08-08 16:30 GMT+08:00 Peter Zijlstra <pet...@infradead.org>: > On Tue, Aug 08, 2017 at 08:53:10PM +0800, Yafang Shao wrote: >> Sometimes we want to get tasks in TASK_RUNNING sepcifically, >> instead of dump all tasks. >> For example, when the loadavg are high, we want to dump >> tasks in TASK_RUNNING and TASK_UNINTERRUPTIBLE, which contribute >> to system load. But mostly there're lots of tasks in Sleep state, >> which occupies almost all of the kernel log buffer, even overflows >> it, that causes the useful messages get lost. Although we can >> enlarge the kernel log buffer, but that's not a good idea. >> >> So I made this change to make the show_state_filter more flexible, >> and then we can dump the tasks in TASK_RUNNING specifically. > > It reads like magic and I really don't see the point.