Re: [PATCH] lib: make sg_pool explicitly non-modular

[Ming Lin]

On Wed, 2016-04-20 at 15:13 -0400, Paul Gortmaker wrote:
> The recently added Kconfig controlling compilation of this code is:
> 
> lib/Kconfig:config SG_POOL
> lib/Kconfig:    def_bool n
> 
> ...meaning that it currently is not being built as a module by anyone.
> 
> Lets remove the modular code that is essentially orphaned, so that
> when reading the driver there is no doubt it is builtin-only.
> 
> Since module_init translates to device_initcall in the non-modular
> case, the init ordering remains unchanged with this commit.  However
> one might want to consider moving it to subsys_initcall if it is to
> be ready ahead of SCSI drivers wanting this and using device_initcall.
> 
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Ming Lin <ming.l@xxxxxxxxxxxxxxx>
> Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
> Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
> Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
> ---
>  lib/sg_pool.c | 17 ++---------------
>  1 file changed, 2 insertions(+), 15 deletions(-)
> 
> diff --git a/lib/sg_pool.c b/lib/sg_pool.c
> index 6dd30615a201..e2cf548b9610 100644
> --- a/lib/sg_pool.c
> +++ b/lib/sg_pool.c
> @@ -1,4 +1,4 @@
> -#include <linux/module.h>
> +#include <linux/init.h>
>  #include <linux/scatterlist.h>
>  #include <linux/mempool.h>
>  #include <linux/slab.h>
> @@ -156,17 +156,4 @@ cleanup_sdb:
>  
>  	return -ENOMEM;
>  }
> -
> -static __exit void sg_pool_exit(void)
> -{
> -	int i;
> -
> -	for (i = 0; i < SG_MEMPOOL_NR; i++) {
> -		struct sg_pool *sgp = sg_pools + i;
> -		mempool_destroy(sgp->pool);
> -		kmem_cache_destroy(sgp->slab);
> -	}
> -}
> -
> -module_init(sg_pool_init);
> -module_exit(sg_pool_exit);
> +device_initcall(sg_pool_init);

For SCSI it's OK because always CONFIG_SCSI=y

But we may have a kernel .config with !CONFIG_SCSI and other
non-block-device driver may use this sg_pool.

So the .config will have CONFIG_SG_POOL=m