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

From: KOSAKI Motohiro
Date: Tue Nov 10 2009 - 19:04:56 EST


> On Tue, 2009-11-10 at 14:27 +0900, KOSAKI Motohiro wrote:
> > 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.
>
> I cc'ed you on the updated patch which addresses this. Please let me
> know if you have specific concerns there.
>
> > - ps (and other procps tools) already support /proc/{pid}/cmdline.
> > - task->comm is restrected 16 character length, /proc/cmdline isn't.
>
> Part of the reason to use comm is that most tools like perf or oprofile,
> use comm, instead of cmd.

Ah, good reason. Okey, I will revew your new patch.

thanks.


> Additionally, looking at cmdline, that's per
> mm not per task, right? So it wouldn't really work for thread names.

Currently, yes. I meaned I think you can enhance it ;)

> Please correct me if I'm not seeing what you're really suggesting.



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/