32-bit accesses are shorter than 64-bit accesses on x86_64.
Nothing uses 64-bitness of struct task_struct::state.
Propagate 32-bitness to other variables and functions.
Silently delete "extern" from prototypes.
Signed-off-by: Alexey Dobriyan <[email protected]>
---
block/blk-mq.c | 2 +-
drivers/md/dm.c | 6 +++---
fs/userfaultfd.c | 4 ++--
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 | 10 +++++-----
lib/syscall.c | 2 +-
14 files changed, 29 insertions(+), 29 deletions(-)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3841,7 +3841,7 @@ 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
@@ -2253,7 +2253,7 @@ static bool md_in_flight_bios(struct mapped_device *md)
return sum != 0;
}
-static int dm_wait_for_bios_completion(struct mapped_device *md, long task_state)
+static int dm_wait_for_bios_completion(struct mapped_device *md, int task_state)
{
int r = 0;
DEFINE_WAIT(wait);
@@ -2276,7 +2276,7 @@ static int dm_wait_for_bios_completion(struct mapped_device *md, long task_state
return r;
}
-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;
@@ -2403,7 +2403,7 @@ 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
@@ -339,7 +339,7 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
return ret;
}
-static inline long userfaultfd_get_blocking_state(unsigned int flags)
+static inline int userfaultfd_get_blocking_state(unsigned int flags)
{
if (flags & FAULT_FLAG_INTERRUPTIBLE)
return TASK_INTERRUPTIBLE;
@@ -372,7 +372,7 @@ 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;
- 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
@@ -655,7 +655,7 @@ 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
@@ -1806,10 +1806,10 @@ static __always_inline void scheduler_ipi(void)
*/
preempt_fold_need_resched();
}
-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
@@ -381,7 +381,7 @@ static inline int fatal_signal_pending(struct task_struct *p)
return task_sigpending(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
@@ -58,7 +58,7 @@ 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
@@ -430,7 +430,7 @@ 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;
@@ -446,7 +446,7 @@ 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
@@ -923,7 +923,7 @@ __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)
{
@@ -1097,14 +1097,14 @@ __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
@@ -1600,10 +1600,10 @@ 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
@@ -453,7 +453,7 @@ static void rcu_check_gp_kthread_starvation(void)
unsigned long j;
if (rcu_is_gp_kthread_starving(&j)) {
- 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),
data_race(rcu_state.gp_flags),
@@ -679,9 +679,9 @@ void show_rcu_gp_kthreads(void)
ja = j - data_race(rcu_state.gp_activity);
jr = j - data_race(rcu_state.gp_req_activity);
jw = j - data_race(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, t ? t->state : 0x1ffffL,
+ rcu_state.gp_state, t ? t->state : 0x1ffff,
ja, jr, jw, (long)data_race(rcu_state.gp_wake_seq),
(long)data_race(rcu_state.gp_seq),
(long)data_race(rcu_get_root()->gp_seq_needed),
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2589,7 +2589,7 @@ 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;
@@ -4960,7 +4960,7 @@ static void __sched notrace __schedule(bool preempt)
{
struct task_struct *prev, *next;
unsigned long *switch_count;
- unsigned long prev_state;
+ int prev_state;
struct rq_flags rf;
struct rq *rq;
int cpu;
@@ -7011,7 +7011,7 @@ 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)
@@ -7032,7 +7032,7 @@ 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;
@@ -7912,7 +7912,7 @@ 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
@@ -68,7 +68,7 @@ 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)
Creating 2**32 tasks to wait in D-state is impossible and wasteful.
Return "unsigned int" and save on REX prefixes.
Signed-off-by: Alexey Dobriyan <[email protected]>
---
fs/proc/stat.c | 2 +-
include/linux/sched/stat.h | 2 +-
kernel/sched/core.c | 4 ++--
3 files changed, 4 insertions(+), 4 deletions(-)
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -201,7 +201,7 @@ static int show_stat(struct seq_file *p, void *v)
"btime %llu\n"
"processes %lu\n"
"procs_running %u\n"
- "procs_blocked %lu\n",
+ "procs_blocked %u\n",
nr_context_switches(),
(unsigned long long)boottime.tv_sec,
total_forks,
--- a/include/linux/sched/stat.h
+++ b/include/linux/sched/stat.h
@@ -18,7 +18,7 @@ DECLARE_PER_CPU(unsigned long, process_counts);
extern int nr_processes(void);
unsigned int nr_running(void);
extern bool single_task_running(void);
-extern unsigned long nr_iowait(void);
+unsigned int nr_iowait(void);
extern unsigned long nr_iowait_cpu(int cpu);
static inline int sched_info_on(void)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4418,9 +4418,9 @@ unsigned long nr_iowait_cpu(int cpu)
* Task CPU affinities can make all that even more 'interesting'.
*/
-unsigned long nr_iowait(void)
+unsigned int nr_iowait(void)
{
- unsigned long i, sum = 0;
+ unsigned int i, sum = 0;
for_each_possible_cpu(i)
sum += nr_iowait_cpu(i);
Make
struct dl_rq::dl_nr_migratory
struct dl_rq::dl_nr_running
struct rt_rq::rt_nr_boosted
struct rt_rq::rt_nr_migratory
struct rt_rq::rt_nr_total
struct rq::nr_uninterruptible
32-bit.
If total number of tasks can't exceed 2**32 (and less due to futex pid
limits), then per-runqueue counters can't as well.
This patchset has been sponsored by REX Prefix Eradication Society.
Signed-off-by: Alexey Dobriyan <[email protected]>
---
kernel/sched/loadavg.c | 2 +-
kernel/sched/sched.h | 12 ++++++------
2 files changed, 7 insertions(+), 7 deletions(-)
--- a/kernel/sched/loadavg.c
+++ b/kernel/sched/loadavg.c
@@ -81,7 +81,7 @@ long calc_load_fold_active(struct rq *this_rq, long adjust)
long nr_active, delta = 0;
nr_active = this_rq->nr_running - adjust;
- nr_active += (long)this_rq->nr_uninterruptible;
+ nr_active += (int)this_rq->nr_uninterruptible;
if (nr_active != this_rq->calc_load_active) {
delta = nr_active - this_rq->calc_load_active;
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -622,8 +622,8 @@ struct rt_rq {
} highest_prio;
#endif
#ifdef CONFIG_SMP
- unsigned long rt_nr_migratory;
- unsigned long rt_nr_total;
+ unsigned int rt_nr_migratory;
+ unsigned int rt_nr_total;
int overloaded;
struct plist_head pushable_tasks;
@@ -637,7 +637,7 @@ struct rt_rq {
raw_spinlock_t rt_runtime_lock;
#ifdef CONFIG_RT_GROUP_SCHED
- unsigned long rt_nr_boosted;
+ unsigned int rt_nr_boosted;
struct rq *rq;
struct task_group *tg;
@@ -654,7 +654,7 @@ struct dl_rq {
/* runqueue is an rbtree, ordered by deadline */
struct rb_root_cached root;
- unsigned long dl_nr_running;
+ unsigned int dl_nr_running;
#ifdef CONFIG_SMP
/*
@@ -668,7 +668,7 @@ struct dl_rq {
u64 next;
} earliest_dl;
- unsigned long dl_nr_migratory;
+ unsigned int dl_nr_migratory;
int overloaded;
/*
@@ -946,7 +946,7 @@ struct rq {
* one CPU and if it got migrated afterwards it may decrease
* it on another CPU. Always updated under the runqueue lock:
*/
- unsigned long nr_uninterruptible;
+ unsigned int nr_uninterruptible;
struct task_struct __rcu *curr;
struct task_struct *idle;
On Sat, Feb 06, 2021 at 06:18:32PM +0300, Alexey Dobriyan wrote:
> Silently delete "extern" from prototypes.
NAK, extern is right.
On Sat, Feb 06, 2021 at 06:18:32PM +0300, Alexey Dobriyan wrote:
> 32-bit accesses are shorter than 64-bit accesses on x86_64.
> Nothing uses 64-bitness of struct task_struct::state.
>
> Propagate 32-bitness to other variables and functions.
You're saving a handful of bytes, why?
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -655,7 +655,7 @@ struct task_struct {
> struct thread_info thread_info;
> #endif
> /* -1 unrunnable, 0 runnable, >0 stopped: */
> - volatile long state;
> + volatile int state;
A much larger, but probably more useful cleanup would be to get rid of
that volatile.
On Mon, Feb 08, 2021 at 11:34:18AM +0100, Peter Zijlstra wrote:
> On Sat, Feb 06, 2021 at 06:18:32PM +0300, Alexey Dobriyan wrote:
>
> > Silently delete "extern" from prototypes.
>
> NAK, extern is right.
Extern is only necessary for variables.
On Mon, Feb 08, 2021 at 11:39:25AM +0100, Peter Zijlstra wrote:
> On Sat, Feb 06, 2021 at 06:18:32PM +0300, Alexey Dobriyan wrote:
> > 32-bit accesses are shorter than 64-bit accesses on x86_64.
> > Nothing uses 64-bitness of struct task_struct::state.
> >
> > Propagate 32-bitness to other variables and functions.
>
> You're saving a handful of bytes, why?
Eeh? To save handful of bytes.
> > --- a/include/linux/sched.h
> > +++ b/include/linux/sched.h
> > @@ -655,7 +655,7 @@ struct task_struct {
> > struct thread_info thread_info;
> > #endif
> > /* -1 unrunnable, 0 runnable, >0 stopped: */
> > - volatile long state;
> > + volatile int state;
>
> A much larger, but probably more useful cleanup would be to get rid of
> that volatile.
volatile is separate patch. It is independent of ->state type.
I didn't think about this specific volatile at all.
On Mon, Feb 08, 2021 at 05:30:25PM +0300, Alexey Dobriyan wrote:
> On Mon, Feb 08, 2021 at 11:34:18AM +0100, Peter Zijlstra wrote:
> > On Sat, Feb 06, 2021 at 06:18:32PM +0300, Alexey Dobriyan wrote:
> >
> > > Silently delete "extern" from prototypes.
> >
> > NAK, extern is right.
>
> Extern is only necessary for variables.
Specifically C17, 6.2.2 p5 (linkage of identifiers):
if the declaration of an identifier for a function has no
storage-class specifier, its linkage is determined exactly as if
it were declared with the storage-class specifier "extern".
This is why nothing happens if "extern" is deleted.
On Mon, Feb 08, 2021 at 05:52:45PM +0300, Alexey Dobriyan wrote:
> On Mon, Feb 08, 2021 at 05:30:25PM +0300, Alexey Dobriyan wrote:
> > On Mon, Feb 08, 2021 at 11:34:18AM +0100, Peter Zijlstra wrote:
> > > On Sat, Feb 06, 2021 at 06:18:32PM +0300, Alexey Dobriyan wrote:
> > >
> > > > Silently delete "extern" from prototypes.
> > >
> > > NAK, extern is right.
> >
> > Extern is only necessary for variables.
>
> Specifically C17, 6.2.2 p5 (linkage of identifiers):
>
> if the declaration of an identifier for a function has no
> storage-class specifier, its linkage is determined exactly as if
> it were declared with the storage-class specifier "extern".
>
> This is why nothing happens if "extern" is deleted.
I know, but I still very much like extern on the function declarations
too. It tells me the definition isn't to be found in this TU.
On Mon, Feb 08, 2021 at 04:25:35PM +0100, Peter Zijlstra wrote:
> On Mon, Feb 08, 2021 at 05:52:45PM +0300, Alexey Dobriyan wrote:
> > On Mon, Feb 08, 2021 at 05:30:25PM +0300, Alexey Dobriyan wrote:
> > > On Mon, Feb 08, 2021 at 11:34:18AM +0100, Peter Zijlstra wrote:
> > > > On Sat, Feb 06, 2021 at 06:18:32PM +0300, Alexey Dobriyan wrote:
> > > >
> > > > > Silently delete "extern" from prototypes.
> > > >
> > > > NAK, extern is right.
> > >
> > > Extern is only necessary for variables.
> >
> > Specifically C17, 6.2.2 p5 (linkage of identifiers):
> >
> > if the declaration of an identifier for a function has no
> > storage-class specifier, its linkage is determined exactly as if
> > it were declared with the storage-class specifier "extern".
> >
> > This is why nothing happens if "extern" is deleted.
>
> I know, but I still very much like extern on the function declarations
> too. It tells me the definition isn't to be found in this TU.
What can I say. The absense of function body should tell that.