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Wed, 21 Oct 2026 15:01:11 -0700 (PDT) Received: from localhost ([153.61.198.252]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-8a0895c05f4sm1334306b3a.28.2026.10.21.15.01.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 21 Oct 2026 15:01:11 -0700 (PDT) Content-Type: text/plain; charset=UTF-8 Date: Wed, 21 Oct 2026 22:01:10 +0000 Message-Id: Subject: Re: [PATCH v4 0/2] tracing: fgraph: fix the quadratic shadow stack walk From: "Alexei Starovoitov" To: "Vineet Gupta" , , Cc: , , , , , , , In-Reply-To: <20261021174406.2891598-1-vineet.gupta@linux.dev> References: <20261021174406.2891598-1-vineet.gupta@linux.dev> X-Mailer: mkdraft (claude review draft; edit before sending) 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 Wed, Oct 21, 2026 at 10:44 AM Vineet Gupta wrote: > On a 60-core Sapphire Rapids machine with 400000 idle threads it took > 227 s, inside a single bpf() syscall for the kprobe_multi case. Acked-by: Alexei Starovoitov