Re: [PATCHv6 1/3] rdmacg: Added rdma cgroup controller

[Leon Romanovsky]

On Sat, Feb 20, 2016 at 04:30:04PM +0530, Parav Pandit wrote:
> Added rdma cgroup controller that does accounting, limit enforcement
> on rdma/IB verbs and hw resources.
> 
> Added rdma cgroup header file which defines its APIs to perform
> charing/uncharing functionality and device registration which will
> participate in controller functions of accounting and limit
> enforcements. It also define rdmacg_device structure to bind IB stack
> and RDMA cgroup controller.
> 
> RDMA resources are tracked using resource pool. Resource pool is per
> device, per cgroup entity which allows setting up accounting limits
> on per device basis.
> 
> Resources are not defined by the RDMA cgroup, instead they are defined
> by the external module IB stack. This allows extending IB stack
> without changing kernel, as IB stack is going through changes
> and enhancements.
> 
> Resource pool is created/destroyed dynamically whenever
> charging/uncharging occurs respectively and whenever user
> configuration is done. Its a tradeoff of memory vs little more code
> space that creates resource pool whenever necessary,
> instead of creating them during cgroup creation and device registration
> time.
> 
> Signed-off-by: Parav Pandit <pandit.parav@xxxxxxxxx>
> ---
>  include/linux/cgroup_rdma.h   |  53 +++
>  include/linux/cgroup_subsys.h |   4 +
>  init/Kconfig                  |  10 +
>  kernel/Makefile               |   1 +
>  kernel/cgroup_rdma.c          | 753 ++++++++++++++++++++++++++++++++++++++++++
>  5 files changed, 821 insertions(+)
>  create mode 100644 include/linux/cgroup_rdma.h
>  create mode 100644 kernel/cgroup_rdma.c
> 
> diff --git a/include/linux/cgroup_rdma.h b/include/linux/cgroup_rdma.h
> new file mode 100644
> index 0000000..b370733
> --- /dev/null
> +++ b/include/linux/cgroup_rdma.h
> @@ -0,0 +1,53 @@
> +#ifndef _CGROUP_RDMA_H
> +#define _CGROUP_RDMA_H
> +
> +#include <linux/cgroup.h>
> +
> +struct rdma_cgroup {
> +#ifdef CONFIG_CGROUP_RDMA
> +	struct cgroup_subsys_state	css;
> +
> +	spinlock_t rpool_list_lock;	/* protects resource pool list */
> +	struct list_head rpool_head;	/* head to keep track of all resource
> +					 * pools that belongs to this cgroup.
> +					 */
> +#endif
> +};
> +
> +#ifdef CONFIG_CGROUP_RDMA

I'm sure that you already asked about that, but why do you need ifdef
embedded in struct rdma_cgroup and right after that the same one?
Can you place this ifdef before declaring struct rdma_cgroup?

> +
> +struct rdmacg_device;
> +

Thanks