From: Eduard Zingerman <eddyz87@gmail.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>, bpf@vger.kernel.org
Cc: daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org,
memxor@gmail.com, kernel-team@fb.com
Subject: Re: [PATCH v3 bpf-next 0/4] bpf: Introduce may_goto and cond_break
Date: Sat, 02 Mar 2024 03:20:50 +0200 [thread overview]
Message-ID: <3c98f93bb3f0520d01d764ac4d89c66e50cbe633.camel@gmail.com> (raw)
In-Reply-To: <20240301033734.95939-1-alexei.starovoitov@gmail.com>
On Thu, 2024-02-29 at 19:37 -0800, Alexei Starovoitov wrote:
> From: Alexei Starovoitov <ast@kernel.org>
>
> v2 -> v3: Major change
> - drop bpf_can_loop() kfunc and introduce may_goto instruction instead
> kfunc is a function call while may_goto doesn't consume any registers
> and LLVM can produce much better code due to less register pressure.
> - instead of counting from zero to BPF_MAX_LOOPS start from it instead
> and break out of the loop when count reaches zero
> - use may_goto instruction in cond_break macro
> - recognize that 'exact' state comparison doesn't need to be truly exact.
> regsafe() should ignore precision and liveness marks, but range_within
> logic is safe to use while evaluating open coded iterators.
Sorry for the delay, I will look through this patch-set over the weekend.
next prev parent reply other threads:[~2024-03-02 1:20 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-01 3:37 [PATCH v3 bpf-next 0/4] bpf: Introduce may_goto and cond_break Alexei Starovoitov
2024-03-01 3:37 ` [PATCH v3 bpf-next 1/4] bpf: Introduce may_goto instruction Alexei Starovoitov
2024-03-01 3:37 ` [PATCH v3 bpf-next 2/4] bpf: Recognize that two registers are safe when their ranges match Alexei Starovoitov
2024-03-01 3:37 ` [PATCH v3 bpf-next 3/4] bpf: Add cond_break macro Alexei Starovoitov
2024-03-01 3:37 ` [PATCH v3 bpf-next 4/4] selftests/bpf: Test may_goto Alexei Starovoitov
2024-03-01 19:47 ` John Fastabend
2024-03-01 21:16 ` Alexei Starovoitov
2024-03-01 21:47 ` John Fastabend
2024-03-01 22:06 ` John Fastabend
2024-03-01 22:12 ` Alexei Starovoitov
2024-03-01 21:22 ` Alexei Starovoitov
2024-03-01 5:24 ` [PATCH v3 bpf-next 0/4] bpf: Introduce may_goto and cond_break John Fastabend
2024-03-02 1:20 ` Eduard Zingerman [this message]
2024-03-02 1:28 ` Alexei Starovoitov
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