Re: [PATCH] bpf: Convert lpm_trie::lock to 'raw_spinlock_t'

[Alexei Starovoitov]

On Sat, Nov 16, 2024 at 1:21 AM Sebastian Andrzej Siewior
<bigeasy@xxxxxxxxxxxxx> wrote:
>
> On 2024-11-15 23:29:31 [+0100], Thomas Gleixner wrote:
> > IIRC, BPF has it's own allocator which can be used everywhere.
>
> Thomas Weißschuh made something. It appears to work. Need to take a
> closer look.

Any more details?
bpf_mem_alloc is a stop gap.
As Vlastimil Babka suggested long ago:
https://lwn.net/Articles/974138/
"...next on the target list is the special allocator used by the BPF
subsystem. This allocator is intended to succeed in any calling
context, including in non-maskable interrupts (NMIs). BPF maintainer
Alexei Starovoitov is evidently in favor of this removal if SLUB is
able to handle the same use cases..."

Here is the first step:
https://lore.kernel.org/bpf/20241116014854.55141-1-alexei.starovoitov@xxxxxxxxx/