Re: [RFC][PATCH] Add prctl to set sibling thread names

[KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>]

Hi Sean, John,

> Kosaki,
> Here are a couple of use cases previously posted to this thread on the linux kernel mailing list:
> 
> dispatch thread adds context to thread names:
> http://marc.info/?l=linux-kernel&m=125660141231348&w=2
> 
> java language support:
> http://marc.info/?l=linux-kernel&m=125666430720863&w=2
> 
> 
> 
> Here are some various specific use cases from the web:
> 
> Attaching additional info to thread names when used for different purposes:
> http://osdir.com/ml/java.jsr.166-concurrency/2006-12/msg00105.html
> 
> Threads obtained from thread pools being reassigned new names:
> http://haacked.com/archive/2004/06/07/546.aspx
> http://bytes.com/topic/c-sharp/answers/637152-naming-backgroundworker-thread
> 
> Renaming threads scattered across third-party libraries by enumerating them and renaming them dynamically:
> http://stackoverflow.com/questions/467224/renaming-threads-in-java

Okey, good explanation. thanks!

So, I would suggested to extend /proc/{pid}/cmdline instead using task->comm.
because 
  - task->comm has nasty locking rule. It is harder to change SMP safe.
  - ps (and other procps tools) already support /proc/{pid}/cmdline.
  - task->comm is restrected 16 character length, /proc/cmdline isn't.

You can see prctl-add-pr_set_proctitle_area-option.patch in -mm tree
as enhancement example at first step.