Re: WARNING: at mm/page-writeback.c:1990 __set_page_dirty_nobuffers+0x13a/0x170()

[Minchan Kim <minchan@kernel.org>]

On 06/04/2012 10:26 AM, KOSAKI Motohiro wrote:

>> Right. I missed that. I think we can use the page passed to rescue_unmovable_pageblock.
>> We make sure it's valid in isolate_freepages. So how about this?
>>
>> barrios@bbox:~/linux-2.6$ git diff
>> diff --git a/mm/compaction.c b/mm/compaction.c
>> index 4ac338a..7459ab5 100644
>> --- a/mm/compaction.c
>> +++ b/mm/compaction.c
>> @@ -368,11 +368,11 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
>>  static bool rescue_unmovable_pageblock(struct page *page)
>>  {
>>        unsigned long pfn, start_pfn, end_pfn;
>> -       struct page *start_page, *end_page;
>> +       struct page *start_page, *end_page, *cursor_page;
>>
>>        pfn = page_to_pfn(page);
>>        start_pfn = pfn & ~(pageblock_nr_pages - 1);
>> -       end_pfn = start_pfn + pageblock_nr_pages;
>> +       end_pfn = start_pfn + pageblock_nr_pages - 1;
>>
>>        start_page = pfn_to_page(start_pfn);
>>        end_page = pfn_to_page(end_pfn);
>> @@ -381,19 +381,19 @@ static bool rescue_unmovable_pageblock(struct page *page)
>>        if (page_zone(start_page) != page_zone(end_page))
>>                return false;
>>
>> -       for (page = start_page, pfn = start_pfn; page < end_page; pfn++,
>> -                                                                 page++) {
>> +       for (cursor_page = start_page, pfn = start_pfn; cursor_page <= end_page; pfn++,
>> +                                                                 cursor_page++) {
>>                if (!pfn_valid_within(pfn))
>>                        continue;
> 
> I guess  page_zone() should be used after pfn_valid_within(). Why can
> we assume invalid
> pfn return correct zone?


Right you are. We can't make sure it in case of CONFIG_HOLES_IN_ZONE.


-- 
Kind regards,
Minchan Kim

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