[PATCH 1/3] x86/intel_rdt/cqm: Add fix to clear the default RMID during hotcpu

From: Vikas Shivappa
Date: Wed Aug 09 2017 - 14:44:46 EST


The user configured per cpu default RMID is not cleared during cpu
hotplug. This may lead to incorrect RMID values after a cpu goes offline
and again comes back online. Clear the per cpu default RMID during cpu
offline and online handling.

Reported-by: Prakyha Sai Praneeth <sai.praneeth.prakhya@xxxxxxxxx>
Signed-off-by: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/intel_rdt.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index da4f389..4b9edb2 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -551,6 +551,7 @@ static void clear_closid_rmid(int cpu)
struct intel_pqr_state *state = this_cpu_ptr(&pqr_state);

per_cpu(rdt_cpu_default.closid, cpu) = 0;
+ per_cpu(rdt_cpu_default.rmid, cpu) = 0;
state->closid = 0;
state->rmid = 0;
wrmsr(IA32_PQR_ASSOC, 0, 0);
--
1.9.1