linux-kernel - [PATCH] arch_topology: Do not set llc_sibling if llc

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Date:   Sun, 10 Apr 2022 19:36:19 -0700
From:   Qing Wang <wangqing@...o.com>
To:     Sudeep Holla <sudeep.holla@....com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        linux-kernel@...r.kernel.org
Cc:     Wang Qing <wangqing@...o.com>
Subject: [PATCH] arch_topology: Do not set llc_sibling if llc_id is invalid

From: Wang Qing <wangqing@...o.com>

When ACPI is not enabled, cpuid_topo->llc_id = cpu_topo->llc_id = -1, which
will set llc_sibling 0xff(...), this is misleading.

Don't set llc_sibling(default 0) if we don't know the cache topology.

Signed-off-by: Wang Qing <wangqing@...o.com>
---
 drivers/base/arch_topology.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 1d6636e..5c3a642
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -684,7 +684,7 @@ void update_siblings_masks(unsigned int cpuid)
 	for_each_online_cpu(cpu) {
 		cpu_topo = &cpu_topology[cpu];
 
-		if (cpuid_topo->llc_id == cpu_topo->llc_id) {
+		if (cpu_topo->llc_id != -1 && cpuid_topo->llc_id == cpu_topo->llc_id) {
 			cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
 			cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
 		}
-- 
2.7.4