Re: [PATCH bpf-next v2 4/4] selftests: bpf: test non-sleepable arena allocations

[Puranjay Mohan <puranjay@kernel.org>]

Alexei Starovoitov <alexei.starovoitov@gmail.com> writes:

> On Fri, Nov 14, 2025 at 3:17 AM Puranjay Mohan <puranjay@kernel.org> wrote:
>>
>> +
>> +       /* Allocate 2051 pages (more than 1024) at once to test the limit of kmalloc_nolock() */
>> +       pages = bpf_arena_alloc_pages(&arena, NULL, 2051, NUMA_NO_NODE, 0);
>
> Please explain the choice of 2051 a bit better.
> I think you wanted to do 3 steps and last one not aligned to 1024 ?

Yes, I wanted to exercise the loop a couple of times and also do an
iteration that is not aligned to test all edge cases. Will add a better comment.

>> +       if (!pages)
>> +               return -1;
>> +
>> +       bpf_for(i, 0, 2051)
>> +                       pages[i * PAGE_SIZE] = 123;
>> +       bpf_for(i, 0, 2051)
>> +                       if (pages[i * PAGE_SIZE] != 123)
>> +                               return i;
>> +
>> +       bpf_arena_free_pages(&arena, pages, 1025);
>
> free less on purpose?

This is should be 2051 too, missed updating it here.