Re: [PATCH v3 13/24] arm64: Populate cpuinfo after notify_cpu_starting

From	Catalin Marinas <catalin.marinas@arm.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v3 13/24] arm64: Populate cpuinfo after notify_cpu_starting
Date	2015-10-15 13:00 +0200
Message-ID	<qjOql-48a-15@gated-at.bofh.it> (permalink)
References	<qjbyF-4SC-3@gated-at.bofh.it> <qjbIl-53L-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Tue, Oct 13, 2015 at 06:22:21PM +0100, Suzuki K. Poulose wrote:
> This patch delays populating the cpuinfo for a new (hotplugged)
> CPU until the notifiers have executed. This will enable us to verify
> if the new (hotplugged) CPU has all the capabilities which the system
> already has. If it doesn't, we could prevent it from turning online and
> also modifying the system wide feature register status.

Just a question here: do we expect the notifiers to enable certain
features that we check later? AFAICT, the checking is done on the
feature registers which don't change after notifiers, so we could as
well block the booting before any notifier is run.

-- 
Catalin
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Thread

[PATCH v3 00/24] arm64: Consolidate CPU feature handling "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-13 19:30 +0200
  [PATCH v3 23/24] arm64: Expose feature registers by emulating MRS "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-13 19:30 +0200
  [PATCH v3 13/24] arm64: Populate cpuinfo after notify_cpu_starting "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-13 19:40 +0200
    Re: [PATCH v3 13/24] arm64: Populate cpuinfo after  notify_cpu_starting Catalin Marinas <catalin.marinas@arm.com> - 2015-10-15 13:00 +0200
      Re: [PATCH v3 13/24] arm64: Populate cpuinfo after  notify_cpu_starting "Suzuki K. Poulose" <Suzuki.Poulose@arm.com> - 2015-10-15 15:30 +0200
  [PATCH v3 04/24] arm64: Move cpu feature detection code "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-13 19:40 +0200
  [PATCH v3 08/24] arm64: Handle width of a cpuid feature "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-13 19:40 +0200
  [PATCH v3 12/24] arm64: Cleanup mixed endian support detection "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-13 19:40 +0200
  [PATCH v3 19/24] arm64/kvm: Make use of the system wide safe values "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-13 19:40 +0200
  [PATCH v3 06/24] arm64: Move /proc/cpuinfo handling code "Suzuki K. Poulose" <suzuki.poulose@arm.com> - 2015-10-13 19:40 +0200
  Re: [PATCH v3 00/24] arm64: Consolidate CPU feature handling Dave Martin <Dave.Martin@arm.com> - 2015-10-16 17:20 +0200
    Re: [PATCH v3 00/24] arm64: Consolidate CPU feature handling "Suzuki K. Poulose" <Suzuki.Poulose@arm.com> - 2015-10-16 17:40 +0200
      Re: [PATCH v3 00/24] arm64: Consolidate CPU feature handling Dave Martin <Dave.Martin@arm.com> - 2015-10-16 17:50 +0200

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