Re: [PATCH 2/3] z3fold: remove redundant locking

[Vitaly Wool]

On Thu, Oct 20, 2016 at 10:15 PM, Dan Streetman <ddstreet@xxxxxxxx> wrote:
> On Wed, Oct 19, 2016 at 12:35 PM, Vitaly Wool <vitalywool@xxxxxxxxx> wrote:
>> The per-pool z3fold spinlock should generally be taken only when
>> a non-atomic pool variable is modified. There's no need to take it
>> to map/unmap an object. This patch introduces per-page lock that
>> will be used instead to protect per-page variables in map/unmap
>> functions.
>
> I think the per-page lock must be held around almost all access to any
> page zhdr data; previously that was protected by the pool lock.

Right, except for list operations. At this point I think per-page
locks will have to be
thought over again, and there is some nice performance gain from making spinlock
a rwlock anyway, so I'll stick with the latest patchset, fixing tiny
bits like wrong
unbuddied_nr increment in the other patch.

Best regards,
   Vitaly