From 6e086302816b2ced602bc99641eb0189c05f018a Mon Sep 17 00:00:00 2001
From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Date: Mon, 10 Aug 2020 12:48:32 +0530
Subject: [PATCH] powerpc/smp: Allocate cpumask only after searching thread
group
References: jsc#SLE-13617 bsc#1176912 ltc#186322
Patch-mainline: v5.10-rc1
Git-commit: 6e086302816b2ced602bc99641eb0189c05f018a
If allocated earlier and the search fails, then cpu_l1_cache_map cpumask
is unnecessarily cleared. However cpu_l1_cache_map can be allocated /
cleared after we search thread group.
Please note CONFIG_CPUMASK_OFFSTACK is not set on Powerpc. Hence cpumask
allocated by zalloc_cpumask_var_node is never freed.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-9-srikar@linux.vnet.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kernel/smp.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index a44b9350d2ef..41f76c8cd024 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -790,10 +790,6 @@ static int init_cpu_l1_cache_map(int cpu)
if (err)
goto out;
- zalloc_cpumask_var_node(&per_cpu(cpu_l1_cache_map, cpu),
- GFP_KERNEL,
- cpu_to_node(cpu));
-
cpu_group_start = get_cpu_thread_group_start(cpu, &tg);
if (unlikely(cpu_group_start == -1)) {
@@ -802,6 +798,9 @@ static int init_cpu_l1_cache_map(int cpu)
goto out;
}
+ zalloc_cpumask_var_node(&per_cpu(cpu_l1_cache_map, cpu),
+ GFP_KERNEL, cpu_to_node(cpu));
+
for (i = first_thread; i < first_thread + threads_per_core; i++) {
int i_group_start = get_cpu_thread_group_start(i, &tg);
--
2.28.0