Re: [RFC]: fix for recycled thread ids

[Andrew Cagney <cagney at gnu dot org>]

> On Thu, Mar 18, 2004 at 07:36:25PM -0500, Jeff Johnston wrote:
>
> > > The following patch fixes a problem when a user application creates a 
> > > thread shortly after another thread has completed.  For nptl, thread ids 
> > > are addresses. If a thread completes/dies, the tid is available for reuse 
> > >  by a new thread.
>
>
> Does NPTL re-use the TID quickly, or cycle around the way LT did so
> that we only see this under high thread pressure?

Immediatly.  Since they are pointers NPTL re-cycles them as soon as they 
are freed (on the next thread create and, obviously, in preference to 
allocating a new buffer) -- very different to the linuxthreads model.

As a consequence any heavily threaded app quickly shows the problem - 
java (esp eclipse) for instance.

Andrew