Re: [PATCH 0/7] convert semaphore to mutex in struct class

From: Greg KH
Date: Tue Jan 08 2008 - 17:48:46 EST


On Tue, Jan 08, 2008 at 03:05:10PM +0800, Dave Young wrote:
> On Jan 8, 2008 1:20 AM, Greg KH <gregkh@xxxxxxx> wrote:
> > On Mon, Jan 07, 2008 at 06:13:37PM +0100, Stefan Richter wrote:
> > > It's already in the driver core to the most part. It remains to be seen
> > > what is less complicated in the end: Transparent mutex-protected list
> > > accesses provided by driver core (requires the iterator), or all the
> > > necessary locking done by the drivers themselves (requires some more
> > > lock-taking but perhaps fewer lock instances overall in the drivers, and
> > > respective redefinitions and documentation of the driver core API).
> >
> > I favor changing the driver core api and doing this kind of thing there.
> > It keeps the drivers simpler and should hopefully make their lives
> > easier.
>
> What about this?
>
> #define class_for_each_dev(pos, head, member) \
> for (mutex_lock(&(container_of(head, struct class, devices))->mutex), po
> s = list_entry((head)->next, typeof(*pos), member); \
> prefetch(pos->member.next), &pos->member != (head) ? 1 : (mutex_unlock(&
> (container_of(head, struct class, devices))->mutex), 0); \
> pos = list_entry(pos->member.next, typeof(*pos), member))

Eeek, just make the thing a function please, where you pass the iterator
function in, like the driver core has (driver_for_each_device)

thanks,

greg k-h
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