Re: [PATCH V7 1/2] percpu_ref: reduce memory footprint of percpu_ref in fast path

[Tejun Heo]

On Thu, Oct 01, 2020 at 11:48:41PM +0800, Ming Lei wrote:
> 'struct percpu_ref' is often embedded into one user structure, and the
> instance is usually referenced in fast path, however actually only
> 'percpu_count_ptr' is needed in fast path.
> 
> So move other fields into one new structure of 'percpu_ref_data', and
> allocate it dynamically via kzalloc(), then memory footprint of
> 'percpu_ref' in fast path is reduced a lot and becomes suitable to put
> into hot cacheline of user structure.
> 
> Tested-by: Veronika Kabatova <vkabatov@xxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Jens Axboe <axboe@xxxxxxxxx>
> Cc: Bart Van Assche <bvanassche@xxxxxxx>
> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Thanks.

-- 
tejun