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Tue, 03 Nov 2026 19:31:16 -0800 (PST) Received: from localhost ([153.61.198.248]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3b07c9b0ec5sm6956456a91.16.2026.11.03.19.31.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 03 Nov 2026 19:31:15 -0800 (PST) Content-Type: text/plain; charset=UTF-8 Date: Wed, 04 Nov 2026 03:31:15 +0000 Message-Id: Subject: Re: [PATCH bpf-next v3 00/14] bpf: A stack in arena From: "Alexei Starovoitov" To: Cc: , , , In-Reply-To: <20261104012401.1354861-1-alexei.starovoitov@gmail.com> References: <20261104012401.1354861-1-alexei.starovoitov@gmail.com> Content-Transfer-Encoding: 8bit X-Mailing-List: bpf@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 On Tue, Nov 03, 2026 at 05:24 PM Alexei Starovoitov wrote: > No released compiler emits this code. The change to the BPF backend of LLVM > is in review: https://github.com/llvm/llvm-project/pull/235577 The flags are made for Rust. I tried them on C. C without __arena works. The kernel side of this series is enough for it. The LLVM side needs more work. -- libarena without __arena -- '#define __arena' is empty. The compiler moves the globals, the heap and the locals to arena. 63 libarena progs out of 63 pass the verifier. The price against libarena with __arena: two times more casts, JITed code +18%, arena_malloc() +7%. So probably not a recommended approach, but works for "lazy" C developers.