lkml.org 
[lkml]   [2016]   [May]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Question About Functions "__free_pages_check" and "check_new_page" in page_alloc.c
On Mon 16-05-16 21:42:23, Wang Xiaoqiang wrote:
> Hi all,
>
> I am really confused about these two functions. The following code snippet:
>
> if(unlikely(atomic_read(&page->_mapcount) != -1))
> bad_reason ="nonzero mapcount";if(unlikely(page->mapping != NULL))
> bad_reason ="non-NULL mapping";if(unlikely(page_ref_count(page) !=0))
> bad_reason ="nonzero _count";
> ...
> Wouldn't the previous value of "bad_reason" be overwritten by
> the later? Hope to receive from you.

yes it would. Why that would matter. The checks should be in an order
which could give us a more specific reason with later checks. bad_page()
will then print more detailed information.
--
Michal Hocko
SUSE Labs

\
 
 \ /
  Last update: 2016-05-16 17:41    [W:0.036 / U:0.224 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site