Re: [PATCH 1/2] mm/page_owner.c: introduce vmalloc allocator for page_owner

From: Vlastimil Babka
Date: Tue Mar 22 2022 - 11:10:55 EST


On 3/22/22 15:48, Yinan Zhang wrote:
> on 2022/3/22 11:28, Matthew Wilcox wrote:
>
>> On Tue, Mar 22, 2022 at 11:22:24AM +0800, Yinan Zhang wrote:
>>> An application's memory consumption is high and keeps increasing,
>>> then it is suspected of having memory leak. There are several
>>> commonly used memory allocators: slab, cma, vmalloc, etc. The memory
>>> leak identification can be speed up if page information allocated
>>> by an individual allocator are analyzed individually. This patch
>>> introduce vmalloc allocator for page_owner.
>> Why is /proc/vmallocinfo not enough?
>
> There is only one owner information in /proc/vmallocinfo: caller.
> While there are plenty of owner information in page owner,
> besides caller, it includes task id (pid), process id (tgid),
> and other useful information, which enables us for more comprehensive
> page allocation/release relevant statistics and analysis.
>
> Adding allocator infomation can augment page owner for tracking about
> who allocates each page. And this patch adds vmalloc allocator infomation.

Hm but page_owner has the whole stack trace of allocation so it should be
easy to determine vmalloc from slab etc? How exactly would this extra field
help?