From: "Alexei Starovoitov" <alexei.starovoitov@gmail.com>
To: "Kumar Kartikeya Dwivedi" <memxor@gmail.com>, <bpf@vger.kernel.org>
Cc: <daniel@iogearbox.net>, <andrii@kernel.org>, <eddyz87@gmail.com>
Subject: Re: [PATCH bpf-next v3 00/14] bpf: A stack in arena
Date: Wed, 04 Nov 2026 18:02:02 +0000 [thread overview]
Message-ID: <DMMMGML15GX5.3GT3JKTNCB748@gmail.com> (raw)
In-Reply-To: <DMM94NDU83WN.337PKDJT31SOE@gmail.com>
On Tue, Nov 03, 2026 at 11:35 PM Kumar Kartikeya Dwivedi <memxor@gmail.com> wrote:
>> The price against libarena with __arena: two times more casts, JITed code
>> +18%, arena_malloc() +7%.
>
> Could you elaborate on this? Are the extra casts due to the fact that globals,
> heaps, and locals on the stack are moving to arena memory?
exactly.
> My understanding is
> that 1-1, the compiler approach is still more efficient in terms of the casts
> emitted (and 32-bit narrowing) vs BPF_F_ARENA_SCALAR.
Right. llvm adding casts is a clear win over BPF_F_ARENA_SCALAR.
next prev parent reply other threads:[~2026-11-04 18:02 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-04 1:23 [PATCH bpf-next v3 00/14] bpf: A stack in arena Alexei Starovoitov
2026-11-04 1:23 ` [PATCH bpf-next v3 01/14] libbpf: Make arena 4 Gbyte when max_entries is not set Alexei Starovoitov
2026-11-04 1:23 ` [PATCH bpf-next v3 02/14] selftests/bpf: Test the default size of arena Alexei Starovoitov
2026-11-04 1:23 ` [PATCH bpf-next v3 03/14] bpf: Treat addr_space_cast of a pointer that is not in arena as a move Alexei Starovoitov
2026-11-04 2:12 ` bot+bpf-ci
2026-11-04 2:32 ` Alexei Starovoitov
2026-11-04 1:23 ` [PATCH bpf-next v3 04/14] selftests/bpf: Test addr_space_cast of pointers that are not in arena Alexei Starovoitov
2026-11-04 1:40 ` sashiko-bot
2026-11-04 1:23 ` [PATCH bpf-next v3 05/14] libbpf: Support .bss.addr_space.1 section Alexei Starovoitov
2026-11-04 1:59 ` bot+bpf-ci
2026-11-04 1:23 ` [PATCH bpf-next v3 06/14] libbpf: Relocate pointers that are stored in arena Alexei Starovoitov
2026-11-04 1:44 ` sashiko-bot
2026-11-04 2:02 ` Alexei Starovoitov
2026-11-04 2:32 ` Roman Gushchin
2026-11-04 2:37 ` Alexei Starovoitov
2026-11-04 1:59 ` bot+bpf-ci
2026-11-04 2:30 ` Alexei Starovoitov
2026-11-04 1:23 ` [PATCH bpf-next v3 07/14] selftests/bpf: Test pointers in arena and .bss.addr_space.1 Alexei Starovoitov
2026-11-04 1:23 ` [PATCH bpf-next v3 08/14] bpf: Introduce bpf register BPF_REG_ARENA_SP Alexei Starovoitov
2026-11-04 1:23 ` [PATCH bpf-next v3 09/14] bpf: Add stacks for programs to arena Alexei Starovoitov
2026-11-04 1:23 ` [PATCH bpf-next v3 10/14] bpf, x86: Add BPF_ATOMIC_LOCAL Alexei Starovoitov
2026-11-04 1:23 ` [PATCH bpf-next v3 11/14] bpf: Support BPF_REG_ARENA_SP in the verifier Alexei Starovoitov
2026-11-04 2:12 ` bot+bpf-ci
2026-11-04 1:23 ` [PATCH bpf-next v3 12/14] bpf, x86: Support BPF_REG_ARENA_SP Alexei Starovoitov
2026-11-04 1:23 ` [PATCH bpf-next v3 13/14] bpf, arm64: " Alexei Starovoitov
2026-11-04 1:24 ` [PATCH bpf-next v3 14/14] selftests/bpf: Add tests for BPF_REG_ARENA_SP Alexei Starovoitov
2026-11-04 2:12 ` bot+bpf-ci
2026-11-04 2:29 ` Alexei Starovoitov
2026-11-04 3:31 ` [PATCH bpf-next v3 00/14] bpf: A stack in arena Alexei Starovoitov
2026-11-04 7:35 ` Kumar Kartikeya Dwivedi
2026-11-04 18:02 ` Alexei Starovoitov [this message]
2026-11-04 20:10 ` patchwork-bot+netdevbpf
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