diff options
| author | Samuel Neves <sneves@dei.uc.pt> | 2018-02-21 20:50:36 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-30 07:50:30 +0200 |
| commit | b8421da4b57b47dfb9ee9aacfb2612bb188f5aa5 (patch) | |
| tree | 45b23c78850f63abc107231bab175b3b1f80d73b /arch | |
| parent | afc5883b73347e9e0fb35850a704d06f026e1a7b (diff) | |
x86/topology: Update the 'cpu cores' field in /proc/cpuinfo correctly across CPU hotplug operations
[ Upstream commit 4596749339e06dc7a424fc08a15eded850ed78b7 ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 cb945146b7c8..10b22fc6ef5a 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1497,6 +1497,7 @@ static void remove_siblinginfo(int cpu) cpumask_clear(topology_core_cpumask(cpu)); c->phys_proc_id = 0; c->cpu_core_id = 0; + c->booted_cores = 0; cpumask_clear_cpu(cpu, cpu_sibling_setup_mask); recompute_smt_state(); } |