lkml.org 
[lkml]   [2019]   [Jul]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] mm: page_alloc: document kmemleak's non-blockable __GFP_NOFAIL case
From
Date


On 7/15/19 8:18 AM, Qian Cai wrote:
> On Mon, 2019-07-15 at 10:01 -0500, Catalin Marinas wrote:
>> On 15 Jul 2019, at 08:17, Michal Hocko <mhocko@kernel.org> wrote:
>>> On Sat 13-07-19 04:49:04, Yang Shi wrote:
>>>> When running ltp's oom test with kmemleak enabled, the below warning was
>>>> triggerred since kernel detects __GFP_NOFAIL & ~__GFP_DIRECT_RECLAIM is
>>>> passed in:
>>> kmemleak is broken and this is a long term issue. I thought that
>>> Catalin had something to address this.
>> What needs to be done in the short term is revert commit
>> d9570ee3bd1d4f20ce63485f5ef05663866fe6c0. Longer term the solution is to embed
>> kmemleak metadata into the slab so that we don’t have the situation where the
>> primary slab allocation success but the kmemleak metadata fails.
>>
>> I’m on holiday for one more week with just a phone to reply from but feel free
>> to revert the above commit. I’ll follow up with a better solution.
> Well, the reverting will only make the situation worst for the kmemleak under
> memory pressure. In the meantime, if someone wants to push for the mempool

I think this is expected by reverting that commit since kmemleak
metadata could fail. But, it could fail too even though that commit is
not reverted if the context is non-blockable.

> solution with tunable pool sizes along with the reverting, that could be an
> improvement.
>
> https://lore.kernel.org/linux-mm/20190328145917.GC10283@arrakis.emea.arm.com/

\
 
 \ /
  Last update: 2019-07-15 18:58    [W:0.047 / U:0.348 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site