From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 7975F29424; Tue, 24 Oct 2023 16:02:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="G0VPiT0N" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C019C433C7; Tue, 24 Oct 2023 16:02:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698163353; bh=F7gFThJKXxRz67KtPOHXZ1MPyn546aHaKsuQ7HB3hqg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=G0VPiT0NaPFcpVExXTrkeNQPAO04ohPxAd37DPcoJLpOtXMCCjTbSvuBTvMKm6fKL 7+97TChy1Rw9XyE2D4xj290syTx4P7Q0qI+cUomEuI1s01Fdc+0+On0HONlKTWh43O JYqW/Fa9n5BmP1kwOrdU1rcoFgbCPjndXNvWvCiA= Date: Tue, 24 Oct 2023 18:02:30 +0200 From: Greg Kroah-Hartman To: Russell King Cc: linux-pm@vger.kernel.org, loongarch@lists.linux.dev, linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, kvmarm@lists.linux.dev, x86@kernel.org, linux-csky@vger.kernel.org, linux-doc@vger.kernel.org, linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, Salil Mehta , Jean-Philippe Brucker , jianyong.wu@arm.com, justin.he@arm.com, James Morse , "Rafael J. Wysocki" , Yury Norov , Andy Shevchenko , Rasmus Villemoes , Thomas Gleixner , Peter Zijlstra Subject: Re: [PATCH 38/39] cpumask: Add enabled cpumask for present CPUs that can be brought online Message-ID: <2023102411-ascent-plot-04fd@gregkh> References: Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Oct 24, 2023 at 04:19:24PM +0100, Russell King wrote: > From: James Morse > > The 'offline' file in sysfs shows all offline CPUs, including those > that aren't present. User-space is expected to remove not-present CPUs > from this list to learn which CPUs could be brought online. > > CPUs can be present but not-enabled. These CPUs can't be brought online > until the firmware policy changes, which comes with an ACPI notification > that will register the CPUs. > > With only the offline and present files, user-space is unable to > determine which CPUs it can try to bring online. Add a new CPU mask > that shows this based on all the registered CPUs. > > Signed-off-by: James Morse > --- > drivers/base/cpu.c | 10 ++++++++++ > include/linux/cpumask.h | 25 +++++++++++++++++++++++++ > kernel/cpu.c | 3 +++ > 3 files changed, 38 insertions(+) > > diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c > index 2b9cb2667654..f8bf1d4c7d71 100644 > --- a/drivers/base/cpu.c > +++ b/drivers/base/cpu.c > @@ -95,6 +95,7 @@ void unregister_cpu(struct cpu *cpu) > { > int logical_cpu = cpu->dev.id; > > + set_cpu_enabled(logical_cpu, false); > unregister_cpu_under_node(logical_cpu, cpu_to_node(logical_cpu)); > > device_unregister(&cpu->dev); > @@ -273,6 +274,13 @@ static ssize_t print_cpus_offline(struct device *dev, > } > static DEVICE_ATTR(offline, 0444, print_cpus_offline, NULL); > > +static ssize_t print_cpus_enabled(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + return sysfs_emit(buf, "%*pbl\n", cpumask_pr_args(cpu_enabled_mask)); > +} > +static DEVICE_ATTR(enabled, 0444, print_cpus_enabled, NULL); This needs to be documented somewhere in Documentation/ABI/ did I miss that patch? thanks, greg k-h