Re: [PATCH v5 6/8] staging: zcache: fix static variables defined indebug.h but used in mutiple C files

From: Konrad Rzeszutek Wilk
Date: Tue Apr 02 2013 - 11:18:06 EST


On Mon, Apr 1, 2013 at 10:46 PM, Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx> wrote:
> After commit 95bdaee214 ("zcache: Move debugfs code out of zcache-main.c file")
> be merged, most of knods in zcache debugfs just export zero since these variables
> are defined in debug.h but use in multiple C files zcache-main.c and debug.c, in

I think you meant: "are in use in multiple.."
> this case variables can't be treated as shared variables.

You could also shove them in debug.c right? That way if you compile
without CONFIG_DEBUGFS
then you won't get warnings from unused variables?

>
> Signed-off-by: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/staging/zcache/debug.h | 62 +++++++++++++++++-----------------
> drivers/staging/zcache/zcache-main.c | 31 +++++++++++++++++
> 2 files changed, 62 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/staging/zcache/debug.h b/drivers/staging/zcache/debug.h
> index 4bbe49b..8ec82d4 100644
> --- a/drivers/staging/zcache/debug.h
> +++ b/drivers/staging/zcache/debug.h
> @@ -3,9 +3,9 @@
> #ifdef CONFIG_ZCACHE_DEBUG
>
> /* we try to keep these statistics SMP-consistent */
> -static ssize_t zcache_obj_count;
> +extern ssize_t zcache_obj_count;
> static atomic_t zcache_obj_atomic = ATOMIC_INIT(0);
> -static ssize_t zcache_obj_count_max;
> +extern ssize_t zcache_obj_count_max;
> static inline void inc_zcache_obj_count(void)
> {
> zcache_obj_count = atomic_inc_return(&zcache_obj_atomic);
> @@ -17,9 +17,9 @@ static inline void dec_zcache_obj_count(void)
> zcache_obj_count = atomic_dec_return(&zcache_obj_atomic);
> BUG_ON(zcache_obj_count < 0);
> };
> -static ssize_t zcache_objnode_count;
> +extern ssize_t zcache_objnode_count;
> static atomic_t zcache_objnode_atomic = ATOMIC_INIT(0);
> -static ssize_t zcache_objnode_count_max;
> +extern ssize_t zcache_objnode_count_max;
> static inline void inc_zcache_objnode_count(void)
> {
> zcache_objnode_count = atomic_inc_return(&zcache_objnode_atomic);
> @@ -31,9 +31,9 @@ static inline void dec_zcache_objnode_count(void)
> zcache_objnode_count = atomic_dec_return(&zcache_objnode_atomic);
> BUG_ON(zcache_objnode_count < 0);
> };
> -static u64 zcache_eph_zbytes;
> +extern u64 zcache_eph_zbytes;
> static atomic_long_t zcache_eph_zbytes_atomic = ATOMIC_INIT(0);
> -static u64 zcache_eph_zbytes_max;
> +extern u64 zcache_eph_zbytes_max;
> static inline void inc_zcache_eph_zbytes(unsigned clen)
> {
> zcache_eph_zbytes = atomic_long_add_return(clen, &zcache_eph_zbytes_atomic);
> @@ -46,7 +46,7 @@ static inline void dec_zcache_eph_zbytes(unsigned zsize)
> };
> extern u64 zcache_pers_zbytes;
> static atomic_long_t zcache_pers_zbytes_atomic = ATOMIC_INIT(0);
> -static u64 zcache_pers_zbytes_max;
> +extern u64 zcache_pers_zbytes_max;
> static inline void inc_zcache_pers_zbytes(unsigned clen)
> {
> zcache_pers_zbytes = atomic_long_add_return(clen, &zcache_pers_zbytes_atomic);
> @@ -59,7 +59,7 @@ static inline void dec_zcache_pers_zbytes(unsigned zsize)
> }
> extern ssize_t zcache_eph_pageframes;
> static atomic_t zcache_eph_pageframes_atomic = ATOMIC_INIT(0);
> -static ssize_t zcache_eph_pageframes_max;
> +extern ssize_t zcache_eph_pageframes_max;
> static inline void inc_zcache_eph_pageframes(void)
> {
> zcache_eph_pageframes = atomic_inc_return(&zcache_eph_pageframes_atomic);
> @@ -72,7 +72,7 @@ static inline void dec_zcache_eph_pageframes(void)
> };
> extern ssize_t zcache_pers_pageframes;
> static atomic_t zcache_pers_pageframes_atomic = ATOMIC_INIT(0);
> -static ssize_t zcache_pers_pageframes_max;
> +extern ssize_t zcache_pers_pageframes_max;
> static inline void inc_zcache_pers_pageframes(void)
> {
> zcache_pers_pageframes = atomic_inc_return(&zcache_pers_pageframes_atomic);
> @@ -83,21 +83,21 @@ static inline void dec_zcache_pers_pageframes(void)
> {
> zcache_pers_pageframes = atomic_dec_return(&zcache_pers_pageframes_atomic);
> }
> -static ssize_t zcache_pageframes_alloced;
> +extern ssize_t zcache_pageframes_alloced;
> static atomic_t zcache_pageframes_alloced_atomic = ATOMIC_INIT(0);
> static inline void inc_zcache_pageframes_alloced(void)
> {
> zcache_pageframes_alloced = atomic_inc_return(&zcache_pageframes_alloced_atomic);
> };
> -static ssize_t zcache_pageframes_freed;
> +extern ssize_t zcache_pageframes_freed;
> static atomic_t zcache_pageframes_freed_atomic = ATOMIC_INIT(0);
> static inline void inc_zcache_pageframes_freed(void)
> {
> zcache_pageframes_freed = atomic_inc_return(&zcache_pageframes_freed_atomic);
> }
> -static ssize_t zcache_eph_zpages;
> +extern ssize_t zcache_eph_zpages;
> static atomic_t zcache_eph_zpages_atomic = ATOMIC_INIT(0);
> -static ssize_t zcache_eph_zpages_max;
> +extern ssize_t zcache_eph_zpages_max;
> static inline void inc_zcache_eph_zpages(void)
> {
> zcache_eph_zpages = atomic_inc_return(&zcache_eph_zpages_atomic);
> @@ -110,7 +110,7 @@ static inline void dec_zcache_eph_zpages(unsigned zpages)
> }
> extern ssize_t zcache_pers_zpages;
> static atomic_t zcache_pers_zpages_atomic = ATOMIC_INIT(0);
> -static ssize_t zcache_pers_zpages_max;
> +extern ssize_t zcache_pers_zpages_max;
> static inline void inc_zcache_pers_zpages(void)
> {
> zcache_pers_zpages = atomic_inc_return(&zcache_pers_zpages_atomic);
> @@ -130,23 +130,23 @@ static inline unsigned long curr_pageframes_count(void)
> atomic_read(&zcache_pers_pageframes_atomic);
> };
> /* but for the rest of these, counting races are ok */
> -static ssize_t zcache_flush_total;
> -static ssize_t zcache_flush_found;
> -static ssize_t zcache_flobj_total;
> -static ssize_t zcache_flobj_found;
> -static ssize_t zcache_failed_eph_puts;
> -static ssize_t zcache_failed_pers_puts;
> -static ssize_t zcache_failed_getfreepages;
> -static ssize_t zcache_failed_alloc;
> -static ssize_t zcache_put_to_flush;
> -static ssize_t zcache_compress_poor;
> -static ssize_t zcache_mean_compress_poor;
> -static ssize_t zcache_eph_ate_tail;
> -static ssize_t zcache_eph_ate_tail_failed;
> -static ssize_t zcache_pers_ate_eph;
> -static ssize_t zcache_pers_ate_eph_failed;
> -static ssize_t zcache_evicted_eph_zpages;
> -static ssize_t zcache_evicted_eph_pageframes;
> +extern ssize_t zcache_flush_total;
> +extern ssize_t zcache_flush_found;
> +extern ssize_t zcache_flobj_total;
> +extern ssize_t zcache_flobj_found;
> +extern ssize_t zcache_failed_eph_puts;
> +extern ssize_t zcache_failed_pers_puts;
> +extern ssize_t zcache_failed_getfreepages;
> +extern ssize_t zcache_failed_alloc;
> +extern ssize_t zcache_put_to_flush;
> +extern ssize_t zcache_compress_poor;
> +extern ssize_t zcache_mean_compress_poor;
> +extern ssize_t zcache_eph_ate_tail;
> +extern ssize_t zcache_eph_ate_tail_failed;
> +extern ssize_t zcache_pers_ate_eph;
> +extern ssize_t zcache_pers_ate_eph_failed;
> +extern ssize_t zcache_evicted_eph_zpages;
> +extern ssize_t zcache_evicted_eph_pageframes;
>
> extern ssize_t zcache_last_active_file_pageframes;
> extern ssize_t zcache_last_inactive_file_pageframes;
> diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
> index 14dcf8a..e112c1e 100644
> --- a/drivers/staging/zcache/zcache-main.c
> +++ b/drivers/staging/zcache/zcache-main.c
> @@ -145,6 +145,37 @@ ssize_t zcache_pers_zpages;
> u64 zcache_pers_zbytes;
> ssize_t zcache_eph_pageframes;
> ssize_t zcache_pers_pageframes;
> +ssize_t zcache_obj_count;
> +ssize_t zcache_obj_count_max;
> +ssize_t zcache_objnode_count;
> +ssize_t zcache_objnode_count_max;
> +u64 zcache_eph_zbytes;
> +u64 zcache_eph_zbytes_max;
> +u64 zcache_pers_zbytes_max;
> +ssize_t zcache_eph_pageframes_max;
> +ssize_t zcache_pers_pageframes_max;
> +ssize_t zcache_pageframes_alloced;
> +ssize_t zcache_pageframes_freed;
> +ssize_t zcache_eph_zpages;
> +ssize_t zcache_eph_zpages_max;
> +ssize_t zcache_pers_zpages_max;
> +ssize_t zcache_flush_total;
> +ssize_t zcache_flush_found;
> +ssize_t zcache_flobj_total;
> +ssize_t zcache_flobj_found;
> +ssize_t zcache_failed_eph_puts;
> +ssize_t zcache_failed_pers_puts;
> +ssize_t zcache_failed_getfreepages;
> +ssize_t zcache_failed_alloc;
> +ssize_t zcache_put_to_flush;
> +ssize_t zcache_compress_poor;
> +ssize_t zcache_mean_compress_poor;
> +ssize_t zcache_eph_ate_tail;
> +ssize_t zcache_eph_ate_tail_failed;
> +ssize_t zcache_pers_ate_eph;
> +ssize_t zcache_pers_ate_eph_failed;
> +ssize_t zcache_evicted_eph_zpages;
> +ssize_t zcache_evicted_eph_pageframes;
>
> /* Used by this code. */
> ssize_t zcache_last_active_file_pageframes;
> --
> 1.7.7.6
>
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