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Subject[PATCH] sched: make struct task_struct::state 32-bit
32-bit accesses are shorter than 64-bit accesses on x86_64.
Nothing uses 64-bitness of ->state.

Space savings are ~2KB on F30 kernel config.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

arch/ia64/kernel/perfmon.c | 4 ++--
block/blk-mq.c | 2 +-
drivers/md/dm.c | 4 ++--
fs/userfaultfd.c | 2 +-
include/linux/sched.h | 6 +++---
include/linux/sched/debug.h | 2 +-
include/linux/sched/signal.h | 2 +-
kernel/freezer.c | 2 +-
kernel/kthread.c | 4 ++--
kernel/locking/mutex.c | 6 +++---
kernel/locking/semaphore.c | 2 +-
kernel/rcu/rcutorture.c | 4 ++--
kernel/rcu/tree_stall.h | 6 +++---
kernel/sched/core.c | 8 ++++----
lib/syscall.c | 2 +-
15 files changed, 28 insertions(+), 28 deletions(-)

--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -2538,7 +2538,7 @@ pfm_task_incompatible(pfm_context_t *ctx, struct task_struct *task)
if (task == current) return 0;

if (!task_is_stopped_or_traced(task)) {
- DPRINT(("cannot attach to non-stopped task [%d] state=%ld\n", task_pid_nr(task), task->state));
+ DPRINT(("cannot attach to non-stopped task [%d] state=%d\n", task_pid_nr(task), task->state));
return -EBUSY;
}
/*
@@ -4614,7 +4614,7 @@ pfm_check_task_state(pfm_context_t *ctx, int cmd, unsigned long flags)
return 0;
}

- DPRINT(("context %d state=%d [%d] task_state=%ld must_stop=%d\n",
+ DPRINT(("context %d state=%d [%d] task_state=%d must_stop=%d\n",
ctx->ctx_fd,
state,
task_pid_nr(task),
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3471,7 +3471,7 @@ static bool blk_mq_poll_hybrid(struct request_queue *q,
int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin)
{
struct blk_mq_hw_ctx *hctx;
- long state;
+ int state;

if (!blk_qc_t_valid(cookie) ||
!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2424,7 +2424,7 @@ void dm_put(struct mapped_device *md)
}
EXPORT_SYMBOL_GPL(dm_put);

-static int dm_wait_for_completion(struct mapped_device *md, long task_state)
+static int dm_wait_for_completion(struct mapped_device *md, int task_state)
{
int r = 0;
DEFINE_WAIT(wait);
@@ -2570,7 +2570,7 @@ static void unlock_fs(struct mapped_device *md)
* are being added to md->deferred list.
*/
static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
- unsigned suspend_flags, long task_state,
+ unsigned suspend_flags, int task_state,
int dmf_suspended_flag)
{
bool do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG;
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -356,7 +356,7 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
struct userfaultfd_wait_queue uwq;
vm_fault_t ret = VM_FAULT_SIGBUS;
bool must_wait, return_to_userland;
- long blocking_state;
+ int blocking_state;

/*
* We don't do userfault handling for the final child pid update.
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -643,7 +643,7 @@ struct task_struct {
struct thread_info thread_info;
#endif
/* -1 unrunnable, 0 runnable, >0 stopped: */
- volatile long state;
+ volatile int state;

/*
* This begins the randomizable portion of task_struct. Only
@@ -1702,10 +1702,10 @@ extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);

#ifdef CONFIG_SMP
void scheduler_ipi(void);
-extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
+unsigned long wait_task_inactive(struct task_struct *, int match_state);
#else
static inline void scheduler_ipi(void) { }
-static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
+static inline unsigned long wait_task_inactive(struct task_struct *p, int match_state)
{
return 1;
}
--- a/include/linux/sched/debug.h
+++ b/include/linux/sched/debug.h
@@ -14,7 +14,7 @@ extern void dump_cpu_task(int cpu);
/*
* Only dump TASK_* tasks. (0 for all tasks)
*/
-extern void show_state_filter(unsigned long state_filter);
+void show_state_filter(unsigned int state_filter);

static inline void show_state(void)
{
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -367,7 +367,7 @@ static inline int fatal_signal_pending(struct task_struct *p)
return signal_pending(p) && __fatal_signal_pending(p);
}

-static inline int signal_pending_state(long state, struct task_struct *p)
+static inline int signal_pending_state(int state, struct task_struct *p)
{
if (!(state & (TASK_INTERRUPTIBLE | TASK_WAKEKILL)))
return 0;
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -64,7 +64,7 @@ bool __refrigerator(bool check_kthr_stop)
/* Hmm, should we be allowed to suspend when there are realtime
processes around? */
bool was_frozen = false;
- long save = current->state;
+ int save = current->state;

pr_debug("%s entered refrigerator\n", current->comm);

--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -392,7 +392,7 @@ struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
}
EXPORT_SYMBOL(kthread_create_on_node);

-static void __kthread_bind_mask(struct task_struct *p, const struct cpumask *mask, long state)
+static void __kthread_bind_mask(struct task_struct *p, const struct cpumask *mask, int state)
{
unsigned long flags;

@@ -408,7 +408,7 @@ static void __kthread_bind_mask(struct task_struct *p, const struct cpumask *mas
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
}

-static void __kthread_bind(struct task_struct *p, unsigned int cpu, long state)
+static void __kthread_bind(struct task_struct *p, unsigned int cpu, int state)
{
__kthread_bind_mask(p, cpumask_of(cpu), state);
}
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -897,7 +897,7 @@ __ww_mutex_add_waiter(struct mutex_waiter *waiter,
* Lock a mutex (possibly interruptible), slowpath:
*/
static __always_inline int __sched
-__mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
+__mutex_lock_common(struct mutex *lock, int state, unsigned int subclass,
struct lockdep_map *nest_lock, unsigned long ip,
struct ww_acquire_ctx *ww_ctx, const bool use_ww_ctx)
{
@@ -1071,14 +1071,14 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
}

static int __sched
-__mutex_lock(struct mutex *lock, long state, unsigned int subclass,
+__mutex_lock(struct mutex *lock, int state, unsigned int subclass,
struct lockdep_map *nest_lock, unsigned long ip)
{
return __mutex_lock_common(lock, state, subclass, nest_lock, ip, NULL, false);
}

static int __sched
-__ww_mutex_lock(struct mutex *lock, long state, unsigned int subclass,
+__ww_mutex_lock(struct mutex *lock, int state, unsigned int subclass,
struct lockdep_map *nest_lock, unsigned long ip,
struct ww_acquire_ctx *ww_ctx)
{
--- a/kernel/locking/semaphore.c
+++ b/kernel/locking/semaphore.c
@@ -201,7 +201,7 @@ struct semaphore_waiter {
* constant, and thus optimised away by the compiler. Likewise the
* 'timeout' parameter for the cases without timeouts.
*/
-static inline int __sched __down_common(struct semaphore *sem, long state,
+static inline int __sched __down_common(struct semaphore *sem, int state,
long timeout)
{
struct semaphore_waiter waiter;
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1472,10 +1472,10 @@ rcu_torture_stats_print(void)
srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp,
&flags, &gp_seq);
wtp = READ_ONCE(writer_task);
- pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#lx cpu %d\n",
+ pr_alert("??? Writer stall state %s(%d) g%lu f%#x ->state %#x cpu %d\n",
rcu_torture_writer_state_getname(),
rcu_torture_writer_state, gp_seq, flags,
- wtp == NULL ? ~0UL : wtp->state,
+ wtp == NULL ? ~0U : wtp->state,
wtp == NULL ? -1 : (int)task_cpu(wtp));
if (!splatted && wtp) {
sched_show_task(wtp);
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -337,7 +337,7 @@ static void rcu_check_gp_kthread_starvation(void)

j = jiffies - READ_ONCE(rcu_state.gp_activity);
if (j > 2 * HZ) {
- pr_err("%s kthread starved for %ld jiffies! g%ld f%#x %s(%d) ->state=%#lx ->cpu=%d\n",
+ pr_err("%s kthread starved for %ld jiffies! g%ld f%#x %s(%d) ->state=%#x ->cpu=%d\n",
rcu_state.name, j,
(long)rcu_seq_current(&rcu_state.gp_seq),
READ_ONCE(rcu_state.gp_flags),
@@ -559,10 +559,10 @@ void show_rcu_gp_kthreads(void)
ja = j - READ_ONCE(rcu_state.gp_activity);
jr = j - READ_ONCE(rcu_state.gp_req_activity);
jw = j - READ_ONCE(rcu_state.gp_wake_time);
- pr_info("%s: wait state: %s(%d) ->state: %#lx delta ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_flags %#x\n",
+ pr_info("%s: wait state: %s(%d) ->state: %#x delta ->gp_activity %lu ->gp_req_activity %lu ->gp_wake_time %lu ->gp_wake_seq %ld ->gp_seq %ld ->gp_seq_needed %ld ->gp_flags %#x\n",
rcu_state.name, gp_state_getname(rcu_state.gp_state),
rcu_state.gp_state,
- rcu_state.gp_kthread ? rcu_state.gp_kthread->state : 0x1ffffL,
+ rcu_state.gp_kthread ? rcu_state.gp_kthread->state : 0x1ffff,
ja, jr, jw, (long)READ_ONCE(rcu_state.gp_wake_seq),
(long)READ_ONCE(rcu_state.gp_seq),
(long)READ_ONCE(rcu_get_root()->gp_seq_needed),
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1769,7 +1769,7 @@ int migrate_swap(struct task_struct *cur, struct task_struct *p,
* smp_call_function() if an IPI is sent by the same process we are
* waiting to become inactive.
*/
-unsigned long wait_task_inactive(struct task_struct *p, long match_state)
+unsigned long wait_task_inactive(struct task_struct *p, int match_state)
{
int running, queued;
struct rq_flags rf;
@@ -5761,7 +5761,7 @@ void sched_show_task(struct task_struct *p)
EXPORT_SYMBOL_GPL(sched_show_task);

static inline bool
-state_filter_match(unsigned long state_filter, struct task_struct *p)
+state_filter_match(unsigned int state_filter, struct task_struct *p)
{
/* no filter, everything matches */
if (!state_filter)
@@ -5782,7 +5782,7 @@ state_filter_match(unsigned long state_filter, struct task_struct *p)
}


-void show_state_filter(unsigned long state_filter)
+void show_state_filter(unsigned int state_filter)
{
struct task_struct *g, *p;

@@ -6553,7 +6553,7 @@ void __might_sleep(const char *file, int line, int preempt_offset)
*/
WARN_ONCE(current->state != TASK_RUNNING && current->task_state_change,
"do not call blocking ops when !TASK_RUNNING; "
- "state=%lx set at [<%p>] %pS\n",
+ "state=%x set at [<%p>] %pS\n",
current->state,
(void *)current->task_state_change,
(void *)current->task_state_change);
--- a/lib/syscall.c
+++ b/lib/syscall.c
@@ -61,7 +61,7 @@ static int collect_syscall(struct task_struct *target, struct syscall_info *info
*/
int task_current_syscall(struct task_struct *target, struct syscall_info *info)
{
- long state;
+ int state;
unsigned long ncsw;

if (target == current)
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