Re: [PATCH 4/4] drm/ttm: Optimize reservation slightly

[Thomas Hellstrom]

On 11/05/2012 03:01 PM, Maarten Lankhorst wrote:
> Hey,
>
> Op 05-11-12 14:31, Thomas Hellstrom schreef:
> > Reservation locking currently always takes place under the LRU spinlock.
> > Hence, strictly there is no need for an atomic_cmpxchg call; we can use
> > atomic_read followed by atomic_write since nobody else will ever reserve
> > without the lru spinlock held.
> > At least on Intel this should remove a locked bus cycle on successful
> > reserve.
> >
> > Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
> Is that really a good thing to submit when I am busy killing lru lock around reserve? :-)

If your patch series makes it into the same kernel, let's kill this 
patch. Otherwise it may live
at least for a kernel release. It's not a big thing to rebase against, 
and I won't complain if your
patch adds another atomic read-modify-write op here. :)

/Thomas

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