On Sun, 27 Sep 2015 21:04:25 +0000 Alexandru Moise 
<00moses.alexande...@gmail.com> wrote:

> The nr variable is meant to be returned by a function which is
> declared as returning "unsigned long", so declare nr as such.
> 
> Lower down we should also declare delta and nr_pagecache_reclaimable
> as being unsigned longs because they're used to store the values
> returned by zone_page_state() and zone_unmapped_file_pages() which
> also happen to return unsigned integers.

I rewrote the changelog rather a lot:



Subject: mm/vmscan.c: fix types of some locals

In zone_reclaimable_pages(), `nr' is returned by a function which is
declared as returning "unsigned long", so declare it such.  Negative
values are meaningless here.

In zone_pagecache_reclaimable() we should also declare `delta' and
`nr_pagecache_reclaimable' as being unsigned longs because they're used to
store the values returned by zone_page_state() and
zone_unmapped_file_pages() which also happen to return unsigned integers.



> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -194,7 +194,7 @@ static bool sane_reclaim(struct scan_control *sc)
>  
>  static unsigned long zone_reclaimable_pages(struct zone *zone)
>  {
> -     int nr;
> +     unsigned long nr;
>  
>       nr = zone_page_state(zone, NR_ACTIVE_FILE) +
>            zone_page_state(zone, NR_INACTIVE_FILE);

OK.

> @@ -3698,8 +3698,8 @@ static inline unsigned long 
> zone_unmapped_file_pages(struct zone *zone)
>  /* Work out how many page cache pages we can reclaim in this reclaim_mode */
>  static long zone_pagecache_reclaimable(struct zone *zone)
>  {
> -     long nr_pagecache_reclaimable;
> -     long delta = 0;
> +     unsigned long nr_pagecache_reclaimable;
> +     unsigned long delta = 0;
>  
>       /*
>        * If RECLAIM_UNMAP is set, then all file pages are considered

Also OK, because zone_pagecache_reclaimable() takes care to avoid
returning any negative values.


In fact I believe we should also do this:

--- 
a/mm/vmscan.c~mm-fix-declarations-of-nr-delta-and-nr_pagecache_reclaimable-fix
+++ a/mm/vmscan.c
@@ -3693,7 +3693,7 @@ static inline unsigned long zone_unmappe
 }
 
 /* Work out how many page cache pages we can reclaim in this reclaim_mode */
-static long zone_pagecache_reclaimable(struct zone *zone)
+static unsigned long zone_pagecache_reclaimable(struct zone *zone)
 {
        unsigned long nr_pagecache_reclaimable;
        unsigned long delta = 0;
_

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to