Re: [PATCH] net/packet: simply allocations in alloc_one_pg_vec_page

From: Shakeel Butt
Date: Sat May 16 2020 - 19:59:43 EST


On Sat, May 16, 2020 at 4:39 PM David Miller <davem@xxxxxxxxxxxxx> wrote:
>
> From: Shakeel Butt <shakeelb@xxxxxxxxxx>
> Date: Sat, 16 May 2020 15:35:46 -0700
>
> > So, my argument is if non-zero order vzalloc has failed (allocations
> > internal to vzalloc, including virtual mapping allocation and page
> > table allocations, are order 0 and use GFP_KERNEL i.e. triggering
> > reclaim and oom-killer) then the next non-zero order page allocation
> > has very low chance of succeeding.
>
> Also not true.
>
> Page table allocation strategies and limits vary by architecture, they
> may even need virtual mappings themselves. So they can fail in situations
> where a non-zero GFP_KERNEL page allocator allocation would succeed.

Thanks for the explanation. Do you think calling vzalloc only for
non-zero order here has any value?