[PATCH 1/8] percpu: add __percpu sparse annotations to core kernel subsystems

Tejun Heo
2010-01-25T15:20:43Z

Add __percpu sparse annotations to core subsystems.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors. This patch doesn't affect normal builds.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-mm@kvack.org
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Biederman <ebiederm@xmission.com>
---
include/linux/blktrace_api.h | 4 ++--
include/linux/genhd.h | 2 +-
include/linux/kexec.h | 2 +-
include/linux/mmzone.h | 2 +-
include/linux/module.h | 2 +-
include/linux/percpu_counter.h | 2 +-
include/linux/srcu.h | 2 +-
kernel/kexec.c | 2 +-
kernel/sched.c | 4 ++--
kernel/stop_machine.c | 2 +-
mm/percpu.c | 18 ++++++++++--------
11 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 3b73b99..416bf62 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -150,8 +150,8 @@ struct blk_user_trace_setup {
struct blk_trace {
int trace_state;
struct rchan *rchan;
- unsigned long *sequence;
- unsigned char *msg_data;
+ unsigned long __percpu *sequence;
+ unsigned char __percpu *msg_data;
u16 act_mask;
u64 start_lba;
u64 end_lba;
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 9717081..56b5051 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -101,7 +101,7 @@ struct hd_struct {
unsigned long stamp;
int in_flight[2];
#ifdef CONFIG_SMP
- struct disk_stats *dkstats;
+ struct disk_stats __percpu *dkstats;
#else
struct disk_stats dkstats;
#endif
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index c356b69..03e8e8d 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -199,7 +199,7 @@ extern struct kimage *kexec_crash_image;
*/
extern struct resource crashk_res;
typedef u32 note_buf_t[KEXEC_NOTE_BYTES/4];
-extern note_buf_t *crash_notes;
+extern note_buf_t __percpu *crash_notes;
extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
extern size_t vmcoreinfo_size;
extern size_t vmcoreinfo_max_size;
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 7874201..41acd4b 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -301,7 +301,7 @@ struct zone {
unsigned long min_unmapped_pages;
unsigned long min_slab_pages;
#endif
- struct per_cpu_pageset *pageset;
+ struct per_cpu_pageset __percpu *pageset;
/*
* free areas of different sizes
*/
diff --git a/include/linux/module.h b/include/linux/module.h
index 7e74ae0..dd618eb 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -365,7 +365,7 @@ struct module

struct module_ref {
int count;
- } *refptr;
+ } __percpu *refptr;
#endif

#ifdef CONFIG_CONSTRUCTORS
diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h
index a7684a5..9bd103c 100644
--- a/include/linux/percpu_counter.h
+++ b/include/linux/percpu_counter.h
@@ -21,7 +21,7 @@ struct percpu_counter {
#ifdef CONFIG_HOTPLUG_CPU
struct list_head list; /* All percpu_counters are on a list */
#endif
- s32 *counters;
+ s32 __percpu *counters;
};

extern int percpu_counter_batch;
diff --git a/include/linux/srcu.h b/include/linux/srcu.h
index 4765d97..41eedcc 100644
--- a/include/linux/srcu.h
+++ b/include/linux/srcu.h
@@ -33,7 +33,7 @@ struct srcu_struct_array {

struct srcu_struct {
int completed;
- struct srcu_struct_array *per_cpu_ref;
+ struct srcu_struct_array __percpu *per_cpu_ref;
struct mutex mutex;
};

diff --git a/kernel/kexec.c b/kernel/kexec.c
index a9a93d9..c769613 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -40,7 +40,7 @@
#include <asm/sections.h>

/* Per cpu memory for storing cpu states in case of system crash. */
-note_buf_t* crash_notes;
+note_buf_t __percpu *crash_notes;

/* vmcoreinfo stuff */
static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
diff --git a/kernel/sched.c b/kernel/sched.c
index 4508fe7..512b10f 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1566,7 +1566,7 @@ static unsigned long cpu_avg_load_per_task(int cpu)

#ifdef CONFIG_FAIR_GROUP_SCHED

-static __read_mostly unsigned long *update_shares_data;
+static __read_mostly unsigned long __percpu *update_shares_data;

static void __set_se_shares(struct sched_entity *se, unsigned long shares);

@@ -10668,7 +10668,7 @@ struct cgroup_subsys cpu_cgroup_subsys = {
struct cpuacct {
struct cgroup_subsys_state css;
/* cpuusage holds pointer to a u64-type object on every cpu */
- u64 *cpuusage;
+ u64 __percpu *cpuusage;
struct percpu_counter cpustat[CPUACCT_STAT_NSTATS];
struct cpuacct *parent;
};
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 912823e..9bb9fb1 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -45,7 +45,7 @@ static int refcount;
static struct workqueue_struct *stop_machine_wq;
static struct stop_machine_data active, idle;
static const struct cpumask *active_cpus;
-static void *stop_machine_work;
+static void __percpu *stop_machine_work;

static void set_state(enum stopmachine_state newstate)
{
diff --git a/mm/percpu.c b/mm/percpu.c
index b336638..768419d 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -80,13 +80,15 @@
/* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */
#ifndef __addr_to_pcpu_ptr
#define __addr_to_pcpu_ptr(addr) \
- (void *)((unsigned long)(addr) - (unsigned long)pcpu_base_addr \
- + (unsigned long)__per_cpu_start)
+ (void __percpu *)((unsigned long)(addr) - \
+ (unsigned long)pcpu_base_addr + \
+ (unsigned long)__per_cpu_start)
#endif
#ifndef __pcpu_ptr_to_addr
#define __pcpu_ptr_to_addr(ptr) \
- (void *)((unsigned long)(ptr) + (unsigned long)pcpu_base_addr \
- - (unsigned long)__per_cpu_start)
+ (void __force *)((unsigned long)(ptr) + \
+ (unsigned long)pcpu_base_addr - \
+ (unsigned long)__per_cpu_start)
#endif

struct pcpu_chunk {
@@ -1065,7 +1067,7 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void)
* RETURNS:
* Percpu pointer to the allocated area on success, NULL on failure.
*/
-static void *pcpu_alloc(size_t size, size_t align, bool reserved)
+static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved)
{
static int warn_limit = 10;
struct pcpu_chunk *chunk;
@@ -1194,7 +1196,7 @@ fail_unlock_mutex:
* RETURNS:
* Percpu pointer to the allocated area on success, NULL on failure.
*/
-void *__alloc_percpu(size_t size, size_t align)
+void __percpu *__alloc_percpu(size_t size, size_t align)
{
return pcpu_alloc(size, align, false);
}
@@ -1215,7 +1217,7 @@ EXPORT_SYMBOL_GPL(__alloc_percpu);
* RETURNS:
* Percpu pointer to the allocated area on success, NULL on failure.
*/
-void *__alloc_reserved_percpu(size_t size, size_t align)
+void __percpu *__alloc_reserved_percpu(size_t size, size_t align)
{
return pcpu_alloc(size, align, true);
}
@@ -1267,7 +1269,7 @@ static void pcpu_reclaim(struct work_struct *work)
* CONTEXT:
* Can be called from atomic context.
*/
-void free_percpu(void *ptr)
+void free_percpu(void __percpu *ptr)
{
void *addr;
struct pcpu_chunk *chunk;
--
1.6.4.2