[PATCH 2/3] kernel/smp: prepare more CSD lock debugging

From: Juergen Gross
Date: Fri Feb 26 2021 - 06:26:27 EST


In order to be able to easily add more CSD lock debugging data to
struct call_function_data->csd move the call_single_data_t element
into a sub-structure.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
kernel/smp.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/kernel/smp.c b/kernel/smp.c
index d5f0b21ab55e..6d7e6dbe33dc 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -31,8 +31,12 @@

#define CSD_TYPE(_csd) ((_csd)->node.u_flags & CSD_FLAG_TYPE_MASK)

+struct cfd_percpu {
+ call_single_data_t csd;
+};
+
struct call_function_data {
- call_single_data_t __percpu *csd;
+ struct cfd_percpu __percpu *pcpu;
cpumask_var_t cpumask;
cpumask_var_t cpumask_ipi;
};
@@ -55,8 +59,8 @@ int smpcfd_prepare_cpu(unsigned int cpu)
free_cpumask_var(cfd->cpumask);
return -ENOMEM;
}
- cfd->csd = alloc_percpu(call_single_data_t);
- if (!cfd->csd) {
+ cfd->pcpu = alloc_percpu(struct cfd_percpu);
+ if (!cfd->pcpu) {
free_cpumask_var(cfd->cpumask);
free_cpumask_var(cfd->cpumask_ipi);
return -ENOMEM;
@@ -71,7 +75,7 @@ int smpcfd_dead_cpu(unsigned int cpu)

free_cpumask_var(cfd->cpumask);
free_cpumask_var(cfd->cpumask_ipi);
- free_percpu(cfd->csd);
+ free_percpu(cfd->pcpu);
return 0;
}

@@ -694,7 +698,7 @@ static void smp_call_function_many_cond(const struct cpumask *mask,

cpumask_clear(cfd->cpumask_ipi);
for_each_cpu(cpu, cfd->cpumask) {
- call_single_data_t *csd = per_cpu_ptr(cfd->csd, cpu);
+ call_single_data_t *csd = &per_cpu_ptr(cfd->pcpu, cpu)->csd;

if (cond_func && !cond_func(cpu, info))
continue;
@@ -719,7 +723,7 @@ static void smp_call_function_many_cond(const struct cpumask *mask,
for_each_cpu(cpu, cfd->cpumask) {
call_single_data_t *csd;

- csd = per_cpu_ptr(cfd->csd, cpu);
+ csd = &per_cpu_ptr(cfd->pcpu, cpu)->csd;
csd_lock_wait(csd);
}
}
--
2.26.2