Re: [PATCH] fs/proc/page: Skip uninitialized page when iterating page structures

[Waiman Long <longman@redhat.com>]

On 8/26/19 12:08 AM, kbuild test robot wrote:
> Hi Waiman,
>
> Thank you for the patch! Yet something to improve:
>
> [auto build test ERROR on linus/master]
> [cannot apply to v5.3-rc6 next-20190823]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>
> url:    https://github.com/0day-ci/linux/commits/Waiman-Long/fs-proc-page-Skip-uninitialized-page-when-iterating-page-structures/20190826-105836
> config: x86_64-lkp (attached as .config)
> compiler: gcc-7 (Debian 7.4.0-10) 7.4.0
> reproduce:
>         # save the attached .config to linux build tree
>         make ARCH=x86_64 
>
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp@intel.com>
>
> All errors (new ones prefixed by >>):
>
>    fs/proc/page.c: In function 'find_next_zone_range':
>>> fs/proc/page.c:58:2: error: expected ';' before 'for'
>      for (pgdat = first_online_pgdat(); pgdat;
>      ^~~
>    fs/proc/page.c:52:6: warning: unused variable 'i' [-Wunused-variable]
>      int i;
>          ^
>    fs/proc/page.c:51:15: warning: unused variable 'zone' [-Wunused-variable]
>      struct zone *zone;
>                   ^~~~
>    fs/proc/page.c:50:13: warning: unused variable 'pgdat' [-Wunused-variable]
>      pg_data_t *pgdat;
>                 ^~~~~
>    fs/proc/page.c: In function 'pfn_in_zone':
>>> fs/proc/page.c:79:23: error: 'struct zone_range' has no member named 'start'; did you mean 'pfn_start'?
>      return pfn >= range->start && pfn < range->end;
>                           ^~~~~
>                           pfn_start
>>> fs/proc/page.c:79:43: error: 'struct zone_range' has no member named 'end'
>      return pfn >= range->start && pfn < range->end;
>                                               ^~
>    fs/proc/page.c:80:1: warning: control reaches end of non-void function [-Wreturn-type]
>     }
>     ^
>
> vim +58 fs/proc/page.c
>
>     46	
>     47	static void find_next_zone_range(struct zone_range *range)
>     48	{
>     49		unsigned long start, end;
>   > 50		pg_data_t *pgdat;
>   > 51		struct zone *zone;
>     52		int i;
>     53	
>     54		/*
>     55		 * Scan all the zone structures to find the next closest one.
>     56		 */
>     57		start = end = -1UL
>   > 58		for (pgdat = first_online_pgdat(); pgdat;
>     59		     pgdat = next_online_pgdat(pgdat)) {
>     60			for (zone = pgdat->node_zones, i = 0; i < MAX_NR_ZONES;
>     61			     zone++, i++) {
>     62				if (!zone->spanned_pages)
>     63					continue;
>     64				if ((zone->zone_start_pfn >= range->pfn_end) &&
>     65				    (zone->zone_start_pfn < start)) {
>     66					start = zone->zone_start_pfn;
>     67					end   = start + zone->spanned_pages;
>     68				}
>     69			}
>     70		}
>     71		range->pfn_start = start;
>     72		range->pfn_end   = end;
>     73	}
>     74	
>     75	static inline bool pfn_in_zone(unsigned long pfn, struct zone_range *range)
>     76	{
>     77		if (pfn >= range->pfn_end)
>     78			find_next_zone_range(range);
>   > 79		return pfn >= range->start && pfn < range->end;
>     80	}
>     81	
>
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Sorry, I have accidentally sent the old version with syntax error out.
Has posted the right one in v2.

Cheers,
Longman