Re: [PATCH 1/1] mm/page_owner: store page_owner's gfp_mask in stackdepot itself

[Andrew Morton]

On Mon, 17 Jun 2019 15:51:32 +0200 Vlastimil Babka <vbabka@xxxxxxx> wrote:

> On 6/7/19 7:53 AM, Sai Charan Sane wrote:
> > Memory overhead of 4MB is reduced by storing gfp_mask in stackdepot along
> > with stacktrace. Stackdepot memory usage increased by ~100kb for 4GB of RAM.
> > 
> > Page owner logs from dmesg:
> > 	Before patch:
> > 		allocated 20971520 bytes of page_ext
> > 	After patch:
> > 		allocated 16777216 bytes of page_ext
> > 
> > Signed-off-by: Sai Charan Sane <s.charan@xxxxxxxxxxx>
> 
> I don't know, this looks like unneeded abuse to me. In the debug
> scenario when someone boots a kernel with page_owner enabled, does 4MB
> out of 4GB RAM really make a difference?

Thanks.  I'll drop this patch.