lkml.org 
[lkml]   [2012]   [Apr]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC] propagate gfp_t to page table alloc functions
On 04/24/2012 02:16 PM, KAMEZAWA Hiroyuki wrote:

> (2012/04/23 17:55), Minchan Kim wrote:
>
>> As I test some code, I found a problem about deadlock by lockdep.
>> The reason I saw the message is __vmalloc calls map_vm_area which calls
>> pud/pmd_alloc without gfp_t. so although we call __vmalloc with
>> GFP_ATOMIC or GFP_NOIO, it ends up allocating pages with GFP_KERNEL.
>> The should be a BUG. This patch fixes it by passing gfp_to to low page
>> table allocate functions.
>>
>> Signed-off-by: Minchan Kim <minchan@kernel.org>
>
>
> Hmm ? vmalloc should support GFP_ATOMIC ?


I'm not sure but alloc_large_system_hash already has used.
And it's not specific on GFP_ATOMIC.
We have to care of GFP_NOFS and GFP_NOIO to prevent deadlock on reclaim
context.
There are some places to use GFP_NOFS and we don't emit any warning
message in case of that.

>
> And, do we need to change all pud_,pgd_,pmd_,pte_alloc() for users pgtables ?


Maybe.


--
Kind regards,
Minchan Kim


\
 
 \ /
  Last update: 2012-04-24 07:37    [W:0.091 / U:1.368 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site