Re: [patch] user-vm-unlock-2.5.31-A2

[Ingo Molnar]

On Thu, 15 Aug 2002, Jamie Lokier wrote:

>    - intercept all the system calls that might call mmput(); that is,
>      exit() and execve()), just so it can move the thread-specific data
>      (including the stack) onto the "potentially free list".

(there's no need to intercept anything - glibc *is* the only legitimate
code that might call the raw sys_execve() & sys_exit() system-calls.)

>    - free the stack memory as soon as possible after a thread has died,
>      _without_ depending on garbage collection.  What if all the other
>      threads are compute-bound?  There's a lump of unnecessary stack
>      taking up memory for an indefinite time.
> 
> It seems that you're using a futex anyway -- so why not eliminate that
> pesky system call _and_ make sure pthread_join() work if some library
> you're linked to exits without calling pthread_exit()..

so how would it work exactly? My prediction is that you wont be able to
suggest any better methods than what i outlined in the original email, so
the best (and fastest) solution is some (minimal) kernel help.

	Ingo