x86/topology: Update the 'cpu cores' field in /proc/cpuinfo correctly across CPU hotplug operations

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Without this fix, /proc/cpuinfo will display an incorrect amount
of CPU cores, after bringing them offline and online again, as
exemplified below:

  $ cat /proc/cpuinfo | grep cores
  cpu cores	: 4
  cpu cores	: 8
  cpu cores	: 8
  cpu cores	: 20
  cpu cores	: 4
  cpu cores	: 3
  cpu cores	: 2
  cpu cores	: 2

This patch fixes this by always zeroing the booted_cores variable
upon turning off a logical CPU.

Tested-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Samuel Neves <sneves@dei.uc.pt>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jgross@suse.com
Cc: luto@kernel.org
Cc: prarit@redhat.com
Cc: vkuznets@redhat.com
Link: http://lkml.kernel.org/r/20180221205036.5244-1-sneves@dei.uc.pt
Signed-off-by: Ingo Molnar <mingo@kernel.org>

...

This commit is contained in:

Samuel Neves 2018-02-21 20:50:36 +00:00 • committed by Ingo Molnar

parent 0c52f7c549

commit 4596749339

1 changed files with 1 additions and 0 deletions

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arch/x86/kernel/smpboot.c

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