From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793777567; b=iv1IfujW+Gw/f+aK0+2p9Q/NRzChWTY9SMtgUZSJaQbi590jg26oBpoJIgyw+LV5Ihuh oZzGjsIpV7foMw5k+bMAm38fmnOD1qV0UZk9bNspIqDmqq4pJvrad/Uot6VYFau7JGmRr euTApu5OqYPQTzpkd/inIiMa9BzXEUJuMgIEjlMOUX+zyo9ZDl4M5K0ofMg4hx9AHcLK4 pfAEgaFNVjnDwPtiEzIJFq7HJ9Eb/xWxP67L7BBdXmjR7djKpiGaG1YW+DPVS8EeO6Mdn o/ZdilzaAh3q6RUFVcwobByOn41ak4tUR0SHrc9TknOruwKI94k9WFpaUKr2FwdMIOg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793777567; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=1ycD0BV4gVs7u8bqtOM4Z/HOT0u/KQ4oXXM9rPsMJaM=; b=m0dCm8pFglzMV0JFK1N/pWJIadUkDlMFVIXrvdDT/3DQM12C8xxD5I05U2g2LkbMyFdP N89PClxmHs/a4XiL63HnfoJ2izAlYt9cusrv6nClmEsNTDSh70oaOUQjaDBqa9kJgKV9n mFy5dRejFb+/CL+RhDl3et8PGGgD7TiFxSsWidikLZK5M9XHKcVHaWt97ulLX/uK990WX Wrbxe/bpssHZSs5H0jMon0EjvFL2eRlmmOJai9FfyOGmdGYkKd3j5/wmgQ51Oaddqi5Ye 5tDANPZ8hUxIJfQhfbfiz2cTwULHWqfpCgu23Q7BHfa8zEk7ifEFs7MfymTHo7BMkZw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=DqESkm2P; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EBBE4606A329 for ; Wed, 4 Nov 2026 07:32:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=DqESkm2P Received: by smtp.kernel.org (Postfix) with ESMTPSA id 62F771F00919; Wed, 4 Nov 2026 07:32:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793777566; bh=1ycD0BV4gVs7u8bqtOM4Z/HOT0u/KQ4oXXM9rPsMJaM=; h=From:Subject:Reply-To:To:In-Reply-To:References:Date; b=DqESkm2PgxhVDbLXS1psVA/sGjMq5KjxcwE2X9KkGEzc+MFqhfvE5S1n8RaEg0hgw jQ8i9kuDqZXa9GR6u6xPE7BXi25irwqIx4NHPbFHIl++4axeShFdpVgJahhYpg/TvE 27/WEh7hql0f08ZH7LpJ0i/EEYX9DWNYAvrUpir9uC+Cmz1DSxHFmdtrhxgbBmsbWU Aj7sfs59XdPkRD2ghNHrQD/OyI80PDvTJ59ZuE2KpKeUHgpfKYboWJ4HXnqlxCf9/A ApakxrojETjcQVeiuKGbq+dDPHUXDc2sPCbb82S57Qq7nFeQTvgUbCdGGsNKKQ+Qqu 7QFHIm1XS2P0w== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v1 38/41] perf pmu: Probe branch instruction skid Reply-To: sashiko-reviews@lists.linux.dev To: "Ian Rogers" , linux-perf-users@vger.kernel.org In-Reply-To: <20261103234502.1008382-39-irogers@google.com> References: <20261103234502.1008382-1-irogers@google.com> <20261103234502.1008382-39-irogers@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 04 Nov 2026 07:32:46 +0000 X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > Extend perf_pmu__probe() with run_skid_branch_loop() and > probe_pmu_skid() to empirically measure branch instruction skid across > supported precise_ip levels (0..3) on core PMUs. >=20 > For each supported precise_ip level, open a branch sampling event on the > current thread, execute a NOP-runway loop ending in a backward > conditional branch on x86_64, arm64, and riscv, and compute the minimum, > maximum, average, and exact-IP (zero-skid) sample counts from the > recorded ring buffer samples. >=20 > Signed-off-by: Ian Rogers Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261103234502.1008= 382-1-irogers@google.com?part=3D38