[tip: sched/core] sched: Introduce task_is_running()

From: tip-bot2 for Peter Zijlstra
Date: Fri Jun 18 2021 - 07:24:35 EST

The following commit has been merged into the sched/core branch of tip:

Commit-ID: b03fbd4ff24c5f075e58eb19261d5f8b3e40d7c6
Gitweb: https://git.kernel.org/tip/b03fbd4ff24c5f075e58eb19261d5f8b3e40d7c6
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Fri, 11 Jun 2021 10:28:12 +02:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Fri, 18 Jun 2021 11:43:07 +02:00

sched: Introduce task_is_running()

Replace a bunch of 'p->state == TASK_RUNNING' with a new helper:
task_is_running(p).

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Acked-by: Will Deacon <will@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210611082838.222401495@xxxxxxxxxxxxx
---
arch/alpha/kernel/process.c | 2 +-
arch/arc/kernel/stacktrace.c | 2 +-
arch/arm/kernel/process.c | 2 +-
arch/arm64/kernel/process.c | 2 +-
arch/csky/kernel/stacktrace.c | 2 +-
arch/h8300/kernel/process.c | 2 +-
arch/hexagon/kernel/process.c | 2 +-
arch/ia64/kernel/process.c | 4 ++--
arch/m68k/kernel/process.c | 2 +-
arch/mips/kernel/process.c | 2 +-
arch/nds32/kernel/process.c | 2 +-
arch/nios2/kernel/process.c | 2 +-
arch/parisc/kernel/process.c | 4 ++--
arch/powerpc/kernel/process.c | 4 ++--
arch/riscv/kernel/stacktrace.c | 2 +-
arch/s390/kernel/process.c | 2 +-
arch/s390/mm/fault.c | 2 +-
arch/sh/kernel/process_32.c | 2 +-
arch/sparc/kernel/process_32.c | 3 +--
arch/sparc/kernel/process_64.c | 3 +--
arch/um/kernel/process.c | 2 +-
arch/x86/kernel/process.c | 4 ++--
arch/xtensa/kernel/process.c | 2 +-
block/blk-mq.c | 2 +-
include/linux/sched.h | 2 ++
kernel/kcsan/report.c | 2 +-
kernel/locking/lockdep.c | 2 +-
kernel/rcu/tree_plugin.h | 2 +-
kernel/sched/core.c | 6 +++---
kernel/sched/stats.h | 2 +-
kernel/signal.c | 2 +-
kernel/softirq.c | 3 +--
mm/compaction.c | 2 +-
33 files changed, 40 insertions(+), 41 deletions(-)

diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 5112ab9..ef0c08e 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -380,7 +380,7 @@ get_wchan(struct task_struct *p)
{
unsigned long schedule_frame;
unsigned long pc;
- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;
/*
* This one depends on the frame size of schedule(). Do a
diff --git a/arch/arc/kernel/stacktrace.c b/arch/arc/kernel/stacktrace.c
index f73da20..1b9576d 100644
--- a/arch/arc/kernel/stacktrace.c
+++ b/arch/arc/kernel/stacktrace.c
@@ -83,7 +83,7 @@ seed_unwind_frame_info(struct task_struct *tsk, struct pt_regs *regs,
* is safe-kept and BLINK at a well known location in there
*/

- if (tsk->state == TASK_RUNNING)
+ if (task_is_running(tsk))
return -1;

frame_info->task = tsk;
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 6324f4d..fc9e8b3 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -288,7 +288,7 @@ unsigned long get_wchan(struct task_struct *p)
struct stackframe frame;
unsigned long stack_page;
int count = 0;
- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

frame.fp = thread_saved_fp(p);
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index b4bb67f..14f3c19 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -598,7 +598,7 @@ unsigned long get_wchan(struct task_struct *p)
struct stackframe frame;
unsigned long stack_page, ret = 0;
int count = 0;
- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

stack_page = (unsigned long)try_get_task_stack(p);
diff --git a/arch/csky/kernel/stacktrace.c b/arch/csky/kernel/stacktrace.c
index 16ae20a..1b280ef 100644
--- a/arch/csky/kernel/stacktrace.c
+++ b/arch/csky/kernel/stacktrace.c
@@ -115,7 +115,7 @@ unsigned long get_wchan(struct task_struct *task)
{
unsigned long pc = 0;

- if (likely(task && task != current && task->state != TASK_RUNNING))
+ if (likely(task && task != current && !task_is_running(task)))
walk_stackframe(task, NULL, save_wchan, &pc);
return pc;
}
diff --git a/arch/h8300/kernel/process.c b/arch/h8300/kernel/process.c
index 46b1342..2ac27e4 100644
--- a/arch/h8300/kernel/process.c
+++ b/arch/h8300/kernel/process.c
@@ -134,7 +134,7 @@ unsigned long get_wchan(struct task_struct *p)
unsigned long stack_page;
int count = 0;

- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

stack_page = (unsigned long)p;
diff --git a/arch/hexagon/kernel/process.c b/arch/hexagon/kernel/process.c
index c61165c..6a6835f 100644
--- a/arch/hexagon/kernel/process.c
+++ b/arch/hexagon/kernel/process.c
@@ -135,7 +135,7 @@ unsigned long get_wchan(struct task_struct *p)
unsigned long fp, pc;
unsigned long stack_page;
int count = 0;
- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

stack_page = (unsigned long)task_stack_page(p);
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 7e1a152..e56d63f 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -529,7 +529,7 @@ get_wchan (struct task_struct *p)
unsigned long ip;
int count = 0;

- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

/*
@@ -542,7 +542,7 @@ get_wchan (struct task_struct *p)
*/
unw_init_from_blocked_task(&info, p);
do {
- if (p->state == TASK_RUNNING)
+ if (task_is_running(p))
return 0;
if (unw_unwind(&info) < 0)
return 0;
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index da83cc8..db49f90 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -268,7 +268,7 @@ unsigned long get_wchan(struct task_struct *p)
unsigned long fp, pc;
unsigned long stack_page;
int count = 0;
- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

stack_page = (unsigned long)task_stack_page(p);
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index bff080d..73c8e79 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -662,7 +662,7 @@ unsigned long get_wchan(struct task_struct *task)
unsigned long ra = 0;
#endif

- if (!task || task == current || task->state == TASK_RUNNING)
+ if (!task || task == current || task_is_running(task))
goto out;
if (!task_stack_page(task))
goto out;
diff --git a/arch/nds32/kernel/process.c b/arch/nds32/kernel/process.c
index c1327e5..391895b 100644
--- a/arch/nds32/kernel/process.c
+++ b/arch/nds32/kernel/process.c
@@ -239,7 +239,7 @@ unsigned long get_wchan(struct task_struct *p)
unsigned long stack_start, stack_end;
int count = 0;

- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

if (IS_ENABLED(CONFIG_FRAME_POINTER)) {
diff --git a/arch/nios2/kernel/process.c b/arch/nios2/kernel/process.c
index c5f916c..9ff37ba 100644
--- a/arch/nios2/kernel/process.c
+++ b/arch/nios2/kernel/process.c
@@ -223,7 +223,7 @@ unsigned long get_wchan(struct task_struct *p)
unsigned long stack_page;
int count = 0;

- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

stack_page = (unsigned long)p;
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index b144fbe..184ec3c 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -249,7 +249,7 @@ get_wchan(struct task_struct *p)
unsigned long ip;
int count = 0;

- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

/*
@@ -260,7 +260,7 @@ get_wchan(struct task_struct *p)
do {
if (unwind_once(&info) < 0)
return 0;
- if (p->state == TASK_RUNNING)
+ if (task_is_running(p))
return 0;
ip = info.ip;
if (!in_sched_functions(ip))
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 89e34aa..8935c56 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -2084,7 +2084,7 @@ static unsigned long __get_wchan(struct task_struct *p)
unsigned long ip, sp;
int count = 0;

- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

sp = p->thread.ksp;
@@ -2094,7 +2094,7 @@ static unsigned long __get_wchan(struct task_struct *p)
do {
sp = *(unsigned long *)sp;
if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) ||
- p->state == TASK_RUNNING)
+ task_is_running(p))
return 0;
if (count > 0) {
ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index bde85fc..ff467b9 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -132,7 +132,7 @@ unsigned long get_wchan(struct task_struct *task)
{
unsigned long pc = 0;

- if (likely(task && task != current && task->state != TASK_RUNNING))
+ if (likely(task && task != current && !task_is_running(task)))
walk_stackframe(task, NULL, save_wchan, &pc);
return pc;
}
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index e20bed1..7ae5dde 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -180,7 +180,7 @@ unsigned long get_wchan(struct task_struct *p)
struct unwind_state state;
unsigned long ip = 0;

- if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
+ if (!p || p == current || task_is_running(p) || !task_stack_page(p))
return 0;

if (!try_get_task_stack(p))
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 826d017..8ae3dc5 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -702,7 +702,7 @@ static void pfault_interrupt(struct ext_code ext_code,
* interrupt since it must be a leftover of a PFAULT
* CANCEL operation which didn't remove all pending
* completion interrupts. */
- if (tsk->state == TASK_RUNNING)
+ if (task_is_running(tsk))
tsk->thread.pfault_wait = -1;
}
} else {
diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index 1aa508e..717de05 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -186,7 +186,7 @@ unsigned long get_wchan(struct task_struct *p)
{
unsigned long pc;

- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

/*
diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
index 3b97949..93983d6 100644
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -376,8 +376,7 @@ unsigned long get_wchan(struct task_struct *task)
struct reg_window32 *rw;
int count = 0;

- if (!task || task == current ||
- task->state == TASK_RUNNING)
+ if (!task || task == current || task_is_running(task))
goto out;

fp = task_thread_info(task)->ksp + bias;
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index 7afd0a8..d33c58a 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -674,8 +674,7 @@ unsigned long get_wchan(struct task_struct *task)
unsigned long ret = 0;
int count = 0;

- if (!task || task == current ||
- task->state == TASK_RUNNING)
+ if (!task || task == current || task_is_running(task))
goto out;

tp = task_thread_info(task);
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index c501106..457a38d 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -369,7 +369,7 @@ unsigned long get_wchan(struct task_struct *p)
unsigned long stack_page, sp, ip;
bool seen_sched = 0;

- if ((p == NULL) || (p == current) || (p->state == TASK_RUNNING))
+ if ((p == NULL) || (p == current) || task_is_running(p))
return 0;

stack_page = (unsigned long) task_stack_page(p);
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 5e1f381..e52b208 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -931,7 +931,7 @@ unsigned long get_wchan(struct task_struct *p)
unsigned long start, bottom, top, sp, fp, ip, ret = 0;
int count = 0;

- if (p == current || p->state == TASK_RUNNING)
+ if (p == current || task_is_running(p))
return 0;

if (!try_get_task_stack(p))
@@ -975,7 +975,7 @@ unsigned long get_wchan(struct task_struct *p)
goto out;
}
fp = READ_ONCE_NOCHECK(*(unsigned long *)fp);
- } while (count++ < 16 && p->state != TASK_RUNNING);
+ } while (count++ < 16 && !task_is_running(p));

out:
put_task_stack(p);
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 9534ef5..0601653 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -304,7 +304,7 @@ unsigned long get_wchan(struct task_struct *p)
unsigned long stack_page = (unsigned long) task_stack_page(p);
int count = 0;

- if (!p || p == current || p->state == TASK_RUNNING)
+ if (!p || p == current || task_is_running(p))
return 0;

sp = p->thread.sp;
diff --git a/block/blk-mq.c b/block/blk-mq.c
index c86c01b..655db5f 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3926,7 +3926,7 @@ int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin)
if (signal_pending_state(state, current))
__set_current_state(TASK_RUNNING);

- if (current->state == TASK_RUNNING)
+ if (task_is_running(current))
return 1;
if (ret < 0 || !spin)
break;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index ac5a7d2..2cd5635 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -113,6 +113,8 @@ struct task_group;
__TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
TASK_PARKED)

+#define task_is_running(task) (READ_ONCE((task)->state) == TASK_RUNNING)
+
#define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)

#define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
index 13dce3c..56016e8 100644
--- a/kernel/kcsan/report.c
+++ b/kernel/kcsan/report.c
@@ -460,7 +460,7 @@ static void set_other_info_task_blocking(unsigned long *flags,
* We may be instrumenting a code-path where current->state is already
* something other than TASK_RUNNING.
*/
- const bool is_running = current->state == TASK_RUNNING;
+ const bool is_running = task_is_running(current);
/*
* To avoid deadlock in case we are in an interrupt here and this is a
* race with a task on the same CPU (KCSAN_INTERRUPT_WATCHER), provide a
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 7641bd4..4931a93 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -760,7 +760,7 @@ static void lockdep_print_held_locks(struct task_struct *p)
* It's not reliable to print a task's held locks if it's not sleeping
* and it's not the current task.
*/
- if (p->state == TASK_RUNNING && p != current)
+ if (p != current && task_is_running(p))
return;
for (i = 0; i < depth; i++) {
printk(" #%d: ", i);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index ad0156b..4d69620 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2768,7 +2768,7 @@ EXPORT_SYMBOL_GPL(rcu_bind_current_to_nocb);
#ifdef CONFIG_SMP
static char *show_rcu_should_be_on_cpu(struct task_struct *tsp)
{
- return tsp && tsp->state == TASK_RUNNING && !tsp->on_cpu ? "!" : "";
+ return tsp && task_is_running(tsp) && !tsp->on_cpu ? "!" : "";
}
#else // #ifdef CONFIG_SMP
static char *show_rcu_should_be_on_cpu(struct task_struct *tsp)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 75655cd..618c2b5 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5974,7 +5974,7 @@ static inline void sched_submit_work(struct task_struct *tsk)
{
unsigned int task_flags;

- if (!tsk->state)
+ if (task_is_running(tsk))
return;

task_flags = tsk->flags;
@@ -7949,7 +7949,7 @@ again:
if (curr->sched_class != p->sched_class)
goto out_unlock;

- if (task_running(p_rq, p) || p->state)
+ if (task_running(p_rq, p) || !task_is_running(p))
goto out_unlock;

yielded = curr->sched_class->yield_to_task(rq, p);
@@ -8152,7 +8152,7 @@ void sched_show_task(struct task_struct *p)

pr_info("task:%-15.15s state:%c", p->comm, task_state_to_char(p));

- if (p->state == TASK_RUNNING)
+ if (task_is_running(p))
pr_cont(" running task ");
#ifdef CONFIG_DEBUG_STACK_USAGE
free = stack_not_used(p);
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index 111072e..d8f8eb0 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -217,7 +217,7 @@ static inline void sched_info_depart(struct rq *rq, struct task_struct *t)

rq_sched_info_depart(rq, delta);

- if (t->state == TASK_RUNNING)
+ if (task_is_running(t))
sched_info_enqueue(rq, t);
}

diff --git a/kernel/signal.c b/kernel/signal.c
index f7c6ffc..5fc8fcf 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -4719,7 +4719,7 @@ void kdb_send_sig(struct task_struct *t, int sig)
}
new_t = kdb_prev_t != t;
kdb_prev_t = t;
- if (t->state != TASK_RUNNING && new_t) {
+ if (!task_is_running(t) && new_t) {
spin_unlock(&t->sighand->siglock);
kdb_printf("Process is not RUNNING, sending a signal from "
"kdb risks deadlock\n"
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 5ddc3b1..f3a0121 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -92,8 +92,7 @@ static bool ksoftirqd_running(unsigned long pending)

if (pending & SOFTIRQ_NOW_MASK)
return false;
- return tsk && (tsk->state == TASK_RUNNING) &&
- !__kthread_should_park(tsk);
+ return tsk && task_is_running(tsk) && !__kthread_should_park(tsk);
}

#ifdef CONFIG_TRACE_IRQFLAGS
diff --git a/mm/compaction.c b/mm/compaction.c
index 84fde27..725f564 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1955,7 +1955,7 @@ static inline bool is_via_compact_memory(int order)

static bool kswapd_is_running(pg_data_t *pgdat)
{
- return pgdat->kswapd && (pgdat->kswapd->state == TASK_RUNNING);
+ return pgdat->kswapd && task_is_running(pgdat->kswapd);
}

/*