Re: [robust-futex-4] futex: robust futex support

[david singleton <dsingleton@mvista.com>]

On Jan 20, 2006, at 2:18 PM, Andrew Morton wrote:

> Ingo Oeser <ioe-lkml@rameria.de> wrote:
> > > > +	list_for_each_entry_safe(this, next, head, list) {
> > > > +		list_del(&this->list);
> > > > +		kmem_cache_free(robust_futex_cachep, this);
> > > > +	}
> > >
> > > If we're throwing away the entire contents of the list, there's no 
> > > need to
> > > detach items as we go.
> >
> > Couldn't even detach the list elements first by
> >
> > list_splice_init(&mapping->robust_head->robust_list, head);
> >
> > and free the list from "head" after releasing the mutex?
> > This would reduce lock contention, no?
>
> Yes, it would reduce lock contention nicely.

        Incorporated changes suggested by Andrew Morton and Ingo Oeser.

 fs/inode.c            |    2
 include/linux/fs.h    |    4
 include/linux/futex.h |   33 ++++
 init/Kconfig          |    9 +
 kernel/exit.c         |    2
 kernel/futex.c        |  399 
++++++++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 449 insertions(+)



David

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