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

From: David Miller
Date: Sat May 16 2020 - 19:39:41 EST


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.