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| author | Samuel Neves <sneves@dei.uc.pt> | 2018-02-21 20:50:36 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-02-23 08:47:47 +0100 |
| commit | 4596749339e06dc7a424fc08a15eded850ed78b7 (patch) | |
| tree | 2b440c0cf1c225bdd698433b1c8fa6f84f9ef582 /arch | |
| parent | 0c52f7c5499dc708a64742da0cb7eb4f6d94588b (diff) | |
| download | linux-4596749339e06dc7a424fc08a15eded850ed78b7.tar.gz | |
x86/topology: Update the 'cpu cores' field in /proc/cpuinfo correctly across CPU hotplug operations
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>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 9eee25d07586..ff99e2b6fc54 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1437,6 +1437,7 @@ static void remove_siblinginfo(int cpu) cpumask_clear(topology_sibling_cpumask(cpu)); cpumask_clear(topology_core_cpumask(cpu)); c->cpu_core_id = 0; + c->booted_cores = 0; cpumask_clear_cpu(cpu, cpu_sibling_setup_mask); recompute_smt_state(); } |