powerpc/smp: Allocate cpumask only after searching thread group

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

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index a44b935..41f76c8 100644 (file)
--- 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);