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

From: Ming Lin
Date: Wed Apr 20 2016 - 16:29:00 EST


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