Re: [PATCH] Lightweight userspace semaphores...
Rusty Russell (rusty@rustcorp.com.au)
Mon, 25 Feb 2002 12:10:34 +1100
In message <Pine.LNX.4.33.0202241543550.28708-100000@home.transmeta.com> you wr
ite:
>
>
> On Mon, 25 Feb 2002, Rusty Russell wrote:
> > >
> > > sys_sem_create()
> > > sys_sem_destroy()
> >
> > There is no create and destroy (init is purely userspace). There is
> > "this is a semapore: up it". This is a feature.
>
> You have to realize that there are architectures that need special
> initialization and page allocation for semaphores: they need special flags
> in the TLB for "careful access", for example (sometimes the careful access
> ends up being non-cached).
Bugger. How about:
sys_sem_area(void *pagestart, size_t len)
sys_unsem_area(void *pagestart, size_t len)
Is that sufficient? Is sys_unsem_area required at all?
TDB has an arbitrary number of semaphores in the mmap file...
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
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