Re: [PATCH] mm/madvise: Dont poison entire HugeTLB page for single page errors
From: Anshuman Khandual
Date: Sat May 13 2017 - 22:35:25 EST
On 05/12/2017 01:40 PM, Naoya Horiguchi wrote:
> On Thu, Apr 20, 2017 at 04:36:27PM +0530, Anshuman Khandual wrote:
>> Currently soft_offline_page() migrates the entire HugeTLB page, then
>> dequeues it from the active list by making it a dangling HugeTLB page
>> which ofcourse can not be used further and marks the entire HugeTLB
>> page as poisoned. This might be a costly waste of memory if the error
>> involved affects only small section of the entire page.
>>
>> This changes the behaviour so that only the affected page is marked
>> poisoned and then the HugeTLB page is released back to buddy system.
> Hi Anshuman,
>
> This is a good catch, and we can solve this issue now because freeing
> hwpoisoned page (previously forbidden) is available now.
>
> And I'm thinking that the same issue for hard/soft-offline on free
> hugepages can be solved, so I'll submit a patchset which includes
> updated version of your patch.
Sure, thanks Naoya.