From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8F7C54F7998 for ; Mon, 19 Oct 2026 13:34:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792416889; cv=none; b=LrJW0u+LD3fKRrLGRUsYf6LUb2lTMDLCvFErvLGdvfXqAFyevrsG19wMjMIN/8PzIffIvjmnp3i+i+ExSERVKk9mbNUU6f4euD6QFxN4Cq1EEkUZdK4Z84JMWAQbTTVFVnL6J61hW34p9SMKclRWSk8E9WF5+s1Xi+LG2YMMw9k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792416889; c=relaxed/simple; bh=JBmQUOPFmEU8wEEBTXAmbKhHIQ63etfLwdP4ZzrBtgw=; h=Message-ID:From:Subject:To:Cc:In-Reply-To:References:Content-Type: Date; b=NvArh0N22DuHQGCH/DQ4NBC5kSFYxPY7CdL0cbOFFA6LYFs7k9N0aTcK1vjytVTmoKz5LDGYpJAfHlUaFVJFzp7eTHwRarL9OET6IsIRqQdbUItPlEQMofhMU3QT3ConO3xmKxlO2Gcz6Ip3YfonX5cIu4XpYlaryCloNb3TsSM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lq9Drwbr; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lq9Drwbr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F6CE1F000C4; Mon, 19 Oct 2026 13:34:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792416884; bh=JBmQUOPFmEU8wEEBTXAmbKhHIQ63etfLwdP4ZzrBtgw=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=lq9Drwbr4TNlT5Y24nOr5CoT8yLnvmp9xJmA9iNhlB3qgkxSE+K7KMtH/PB0gFB1J 6ipf5XaUKcnAHqlJQMFVc1UY0+huZKRZDEKMl2jG1i2FUIBuXb2580V3wrbuNIctgG CUO3eLZGfMZv4tm4CDnlPPuT8hYM1eoG27Kc19EDANTalYyj7UyjRDaQfQMPHE1rPx QmjOgsePAbQxb8jXvv8XFRRz0/ZXcoChika+L6cNueDJP7Zo1gMlt0bX5a97zEytLg A77/fbSBjHQiodi3wrzBsD2fVifXBUbYKuoJNWqYj0fqcNmXZE3PhYarjRSKpIqUSM D2Y3GXrSydC+A== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [RFC PATCH 20/49] 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: <20261019130856.49711-21-frederic@kernel.org> References: <20261019130856.49711-1-frederic@kernel.org> <20261019130856.49711-21-frederic@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 19 Oct 2026 13:34:44 +0000 Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > 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/20261019130856.4971= 1-1-frederic@kernel.org?part=3D20