Re: [PATCH v3] mm/page_owner: use kvmalloc instead of kmalloc

[Miles Chen]

On Tue, 2018-10-30 at 09:15 +0100, Michal Hocko wrote:
> On Tue 30-10-18 14:55:51, Miles Chen wrote:
> [...]
> > It's a real problem when using page_owner.
> > I found this issue recently: I'm not able to read page_owner information
> > during a overnight test. (error: read failed: Out of memory). I replace
> > kmalloc() with vmalloc() and it worked well.
> 
> Is this with trimming the allocation to a single page and doing shorter
> than requested reads?


I printed out the allocate count on my device the request count is <=
4096. So I tested this scenario by trimming the count to from 4096 to
1024 bytes and it works fine. 

count = count > 1024? 1024: count;

It tested it on both 32bit and 64bit kernel.