Re: [PATCH 1/1] mlock: split the shmlock_user_lock spinlock intoper user_struct spinlock

[Rik van Riel]

On 05/03/2012 02:07 PM, Rik van Riel wrote:
> On 05/03/2012 01:34 PM, rajman mekaco wrote:
> > The user_shm_lock and user_shm_unlock functions use a single global
> > spinlock for protecting the user->locked_shm.
> >
> > This is an overhead for multiple CPUs calling this code even if they
> > are having different user_struct.
> >
> > Remove the global shmlock_user_lock and introduce and use a new
> > spinlock inside of the user_struct structure.
> >
> > Signed-off-by: rajman mekaco<rajman.mekaco@xxxxxxxxx>
>
> Reviewed-by: Rik van Riel <riel@xxxxxxxxxx>

Hold this ... while the patch is correct, Peter raised
a valid concern about its usefulness, which should be
sorted out first.

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