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=1793904179; b=pI4Fn9FQYZ+E7iD/O++3NWdZptUkb9aP56/PWk0LUscp2kUpplgxIyy5D7xH00CO3KM/ dY3GWDfDmxnBeR0r1M5X2G4WuPTUMk26LHM12lNsjCqR1D/5KSBvVhJB2C98tb726fpmh mMVVHGfl5c7oHvXPp7Hdt3GXW8EtaHuzItFBxMT/lCPuzlc9xjnNABmRAugDXXHritxL7 IumT6xKJmDgq2u6KVfCyUKESZe1H3JsT53bJ/ElBthlw7BcgyZ7qbC9ldXyE3yz+dVBc0 01iD5J5y6Yf5gy+ZJViOIg6n1kFMrHnDAr34nIYalba0/32/eHAuHC/501AO0iAIPOg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793904179; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=VsZlGBDeqkbPyVFKgFXWPn+ZnfPjXh1925IHxdPNdd0=; b=IUViPXHBJnqJ4zhCz6UMr2SR1vgJwZb8Sf7ZqAF05RFLhiiA8ocw6+W9MLS87fqw1gDV clKNTYZI1TmA9YBpwWN2Pz+i4ADcfwZ1GV5fWD2t3yfO8rFMSoLsgOtuQataR0MTfJYx3 dIdejylIAW7m2wXASIBcMl5WG6WsKguyjwxmm5lu7ypZ7eiNcT/sMNSvqcv5QuyyS4Ja3 /up8+ccLdLySf9MiaHNUkSobe2WMGvoEamkbOFOvwxsuQX5hE2Drx3Fgc2YTblKnqJ0iu 2GiKGeQiChfNtP9ylOGGjAPtLdRROUghovKmnTWlkXzA1ovyXzisssZTtSYYoBxyi3Q== 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=eusje8Jl; 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 16E24606A32C for ; Thu, 5 Nov 2026 18:42:58 +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=eusje8Jl Received: by smtp.kernel.org (Postfix) with ESMTPSA id A79F91F000C1; Thu, 5 Nov 2026 18:42:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793904178; bh=VsZlGBDeqkbPyVFKgFXWPn+ZnfPjXh1925IHxdPNdd0=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=eusje8JlmBQzkqWxivPke44zn4uuiwcvsQocjUotN+Q8E2BtKtbcYvmH1nY1xc6Li 6MYYgPuciJDktVi4ivPshkeKrOOoVC08z2GPC1lHumc77lZNCbrZeq1hpOR9D1t1Kf ROjvJyzq+nSsX50yWL71G1H122RyPBSAzTXohZJ8v1F2kZg76Ps+jOMAmpeVO7mqzu Yldz/XFXzVHF9ki5nlblTohKCgkonHkpmR4sh1SBLcPpDysZ7aut8q5Xamh1Ekh5EG eeRwCbOetQNqCHHXBI6+Avie3BFKXv91pCdjW6xJstViqrP5JK3/cU/baaTPlJWaHz zphURx6TZB6tA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 20/47] perf: RISC-V: Move CPUHP_AP_PERF_RISCV_STARTING post stop_machine() Reply-To: sashiko-reviews@lists.linux.dev To: "Frederic Weisbecker" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20261105163045.38862-21-frederic@kernel.org> References: <20261105163045.38862-1-frederic@kernel.org> <20261105163045.38862-21-frederic@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 05 Nov 2026 18:42:58 +0000 X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > Between CPUHP_TEARDOWN_CPU and CPUHP_AP_OFFLINE, stop_machine executes > all the teardown callbacks while stopping all CPUs in the system. This > doesn't mix-up well with running RT or isolated tasks. >=20 > In order to transition smoothly from global stop_machine to finer > grained synchronization between teardown callbacks and the other CPUs, > a new stop machine post function has been introduced to be executed > after the main one with IRQs still disabled while other CPUs can exit > stop_machine(). >=20 > The teardown callback here: >=20 > * Disables the per-cpu IRQ > * Disables user-mode access to the CPU counter > * Disables the shared memory snapshot of the CPU PMU. >=20 > All these operations are local to the CPU and should be able to execute > concurrently with other CPUs. >=20 > Move this teardown callback to post stop_machine() accordingly. >=20 > Signed-off-by: Frederic Weisbecker Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261105163045.3886= 2-1-frederic@kernel.org?part=3D20