Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Thomas Gleixner:
 "The scheduler pull request comes with the following updates:

   - Prevent a divide by zero issue by validating the input value of
     sysctl_sched_time_avg

   - Make task state printing consistent all over the place and have
     explicit state characters for IDLE and PARKED so they wont be
     displayed as 'D' state which confuses tools"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/sysctl: Check user input value of sysctl_sched_time_avg
  sched/debug: Add explicit TASK_PARKED printing
  sched/debug: Ignore TASK_IDLE for SysRq-W
  sched/debug: Add explicit TASK_IDLE printing
  sched/tracing: Use common task-state helpers
  sched/tracing: Fix trace_sched_switch task-state printing
  sched/debug: Remove unused variable
  sched/debug: Convert TASK_state to hex
  sched/debug: Implement consistent task-state printing
This commit is contained in:
Linus Torvalds 2017-10-01 12:10:02 -07:00
commit 7e103ace9c
8 changed files with 102 additions and 74 deletions

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@ -119,30 +119,25 @@ static inline void task_name(struct seq_file *m, struct task_struct *p)
* simple bit tests.
*/
static const char * const task_state_array[] = {
"R (running)", /* 0 */
"S (sleeping)", /* 1 */
"D (disk sleep)", /* 2 */
"T (stopped)", /* 4 */
"t (tracing stop)", /* 8 */
"X (dead)", /* 16 */
"Z (zombie)", /* 32 */
/* states in TASK_REPORT: */
"R (running)", /* 0x00 */
"S (sleeping)", /* 0x01 */
"D (disk sleep)", /* 0x02 */
"T (stopped)", /* 0x04 */
"t (tracing stop)", /* 0x08 */
"X (dead)", /* 0x10 */
"Z (zombie)", /* 0x20 */
"P (parked)", /* 0x40 */
/* states beyond TASK_REPORT: */
"I (idle)", /* 0x80 */
};
static inline const char *get_task_state(struct task_struct *tsk)
{
unsigned int state = (tsk->state | tsk->exit_state) & TASK_REPORT;
/*
* Parked tasks do not run; they sit in __kthread_parkme().
* Without this check, we would report them as running, which is
* clearly wrong, so we report them as sleeping instead.
*/
if (tsk->state == TASK_PARKED)
state = TASK_INTERRUPTIBLE;
BUILD_BUG_ON(1 + ilog2(TASK_REPORT) != ARRAY_SIZE(task_state_array)-1);
return task_state_array[fls(state)];
BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != ARRAY_SIZE(task_state_array));
return task_state_array[__get_task_state(tsk)];
}
static inline int get_task_umask(struct task_struct *tsk)

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@ -65,25 +65,23 @@ struct task_group;
*/
/* Used in tsk->state: */
#define TASK_RUNNING 0
#define TASK_INTERRUPTIBLE 1
#define TASK_UNINTERRUPTIBLE 2
#define __TASK_STOPPED 4
#define __TASK_TRACED 8
#define TASK_RUNNING 0x0000
#define TASK_INTERRUPTIBLE 0x0001
#define TASK_UNINTERRUPTIBLE 0x0002
#define __TASK_STOPPED 0x0004
#define __TASK_TRACED 0x0008
/* Used in tsk->exit_state: */
#define EXIT_DEAD 16
#define EXIT_ZOMBIE 32
#define EXIT_DEAD 0x0010
#define EXIT_ZOMBIE 0x0020
#define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
/* Used in tsk->state again: */
#define TASK_DEAD 64
#define TASK_WAKEKILL 128
#define TASK_WAKING 256
#define TASK_PARKED 512
#define TASK_NOLOAD 1024
#define TASK_NEW 2048
#define TASK_STATE_MAX 4096
#define TASK_STATE_TO_CHAR_STR "RSDTtXZxKWPNn"
#define TASK_PARKED 0x0040
#define TASK_DEAD 0x0080
#define TASK_WAKEKILL 0x0100
#define TASK_WAKING 0x0200
#define TASK_NOLOAD 0x0400
#define TASK_NEW 0x0800
#define TASK_STATE_MAX 0x1000
/* Convenience macros for the sake of set_current_state: */
#define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
@ -99,7 +97,8 @@ struct task_group;
/* get_task_state(): */
#define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
__TASK_TRACED | EXIT_ZOMBIE | EXIT_DEAD)
__TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
TASK_PARKED)
#define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
@ -1243,17 +1242,34 @@ static inline pid_t task_pgrp_nr(struct task_struct *tsk)
return task_pgrp_nr_ns(tsk, &init_pid_ns);
}
static inline char task_state_to_char(struct task_struct *task)
#define TASK_REPORT_IDLE (TASK_REPORT + 1)
#define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
static inline unsigned int __get_task_state(struct task_struct *tsk)
{
const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
unsigned long state = task->state;
unsigned int tsk_state = READ_ONCE(tsk->state);
unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
state = state ? __ffs(state) + 1 : 0;
BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
/* Make sure the string lines up properly with the number of task states: */
BUILD_BUG_ON(sizeof(TASK_STATE_TO_CHAR_STR)-1 != ilog2(TASK_STATE_MAX)+1);
if (tsk_state == TASK_IDLE)
state = TASK_REPORT_IDLE;
return state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?';
return fls(state);
}
static inline char __task_state_to_char(unsigned int state)
{
static const char state_char[] = "RSDTtXZPI";
BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
return state_char[state];
}
static inline char task_state_to_char(struct task_struct *tsk)
{
return __task_state_to_char(__get_task_state(tsk));
}
/**

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@ -114,7 +114,10 @@ static inline long __trace_sched_switch_state(bool preempt, struct task_struct *
* Preemption ignores task state, therefore preempted tasks are always
* RUNNING (we will not have dequeued if state != RUNNING).
*/
return preempt ? TASK_RUNNING | TASK_STATE_MAX : p->state;
if (preempt)
return TASK_STATE_MAX;
return __get_task_state(p);
}
#endif /* CREATE_TRACE_POINTS */
@ -152,12 +155,14 @@ TRACE_EVENT(sched_switch,
TP_printk("prev_comm=%s prev_pid=%d prev_prio=%d prev_state=%s%s ==> next_comm=%s next_pid=%d next_prio=%d",
__entry->prev_comm, __entry->prev_pid, __entry->prev_prio,
__entry->prev_state & (TASK_STATE_MAX-1) ?
__print_flags(__entry->prev_state & (TASK_STATE_MAX-1), "|",
{ 1, "S"} , { 2, "D" }, { 4, "T" }, { 8, "t" },
{ 16, "Z" }, { 32, "X" }, { 64, "x" },
{ 128, "K" }, { 256, "W" }, { 512, "P" },
{ 1024, "N" }) : "R",
(__entry->prev_state & (TASK_REPORT_MAX - 1)) ?
__print_flags(__entry->prev_state & (TASK_REPORT_MAX - 1), "|",
{ 0x01, "S" }, { 0x02, "D" }, { 0x04, "T" },
{ 0x08, "t" }, { 0x10, "X" }, { 0x20, "Z" },
{ 0x40, "P" }, { 0x80, "I" }) :
"R",
__entry->prev_state & TASK_STATE_MAX ? "+" : "",
__entry->next_comm, __entry->next_pid, __entry->next_prio)
);

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@ -5166,6 +5166,28 @@ void sched_show_task(struct task_struct *p)
put_task_stack(p);
}
static inline bool
state_filter_match(unsigned long state_filter, struct task_struct *p)
{
/* no filter, everything matches */
if (!state_filter)
return true;
/* filter, but doesn't match */
if (!(p->state & state_filter))
return false;
/*
* When looking for TASK_UNINTERRUPTIBLE skip TASK_IDLE (allows
* TASK_KILLABLE).
*/
if (state_filter == TASK_UNINTERRUPTIBLE && p->state == TASK_IDLE)
return false;
return true;
}
void show_state_filter(unsigned long state_filter)
{
struct task_struct *g, *p;
@ -5188,7 +5210,7 @@ void show_state_filter(unsigned long state_filter)
*/
touch_nmi_watchdog();
touch_all_softlockup_watchdogs();
if (!state_filter || (p->state & state_filter))
if (state_filter_match(state_filter, p))
sched_show_task(p);
}

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@ -466,8 +466,6 @@ static char *task_group_path(struct task_group *tg)
}
#endif
static const char stat_nam[] = TASK_STATE_TO_CHAR_STR;
static void
print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
{

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@ -367,7 +367,8 @@ static struct ctl_table kern_table[] = {
.data = &sysctl_sched_time_avg,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec,
.proc_handler = proc_dointvec_minmax,
.extra1 = &one,
},
#ifdef CONFIG_SCHEDSTATS
{

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@ -656,15 +656,6 @@ int trace_print_lat_context(struct trace_iterator *iter)
return !trace_seq_has_overflowed(s);
}
static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
static int task_state_char(unsigned long state)
{
int bit = state ? __ffs(state) + 1 : 0;
return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
}
/**
* ftrace_find_event - find a registered event
* @type: the type of event to look for
@ -930,8 +921,8 @@ static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
trace_assign_type(field, iter->ent);
T = task_state_char(field->next_state);
S = task_state_char(field->prev_state);
T = __task_state_to_char(field->next_state);
S = __task_state_to_char(field->prev_state);
trace_find_cmdline(field->next_pid, comm);
trace_seq_printf(&iter->seq,
" %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
@ -966,8 +957,8 @@ static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
trace_assign_type(field, iter->ent);
if (!S)
S = task_state_char(field->prev_state);
T = task_state_char(field->next_state);
S = __task_state_to_char(field->prev_state);
T = __task_state_to_char(field->next_state);
trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
field->prev_pid,
field->prev_prio,
@ -1002,8 +993,8 @@ static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
trace_assign_type(field, iter->ent);
if (!S)
S = task_state_char(field->prev_state);
T = task_state_char(field->next_state);
S = __task_state_to_char(field->prev_state);
T = __task_state_to_char(field->next_state);
SEQ_PUT_HEX_FIELD(s, field->prev_pid);
SEQ_PUT_HEX_FIELD(s, field->prev_prio);

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@ -397,10 +397,10 @@ tracing_sched_switch_trace(struct trace_array *tr,
entry = ring_buffer_event_data(event);
entry->prev_pid = prev->pid;
entry->prev_prio = prev->prio;
entry->prev_state = prev->state;
entry->prev_state = __get_task_state(prev);
entry->next_pid = next->pid;
entry->next_prio = next->prio;
entry->next_state = next->state;
entry->next_state = __get_task_state(next);
entry->next_cpu = task_cpu(next);
if (!call_filter_check_discard(call, entry, buffer, event))
@ -425,10 +425,10 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
entry = ring_buffer_event_data(event);
entry->prev_pid = curr->pid;
entry->prev_prio = curr->prio;
entry->prev_state = curr->state;
entry->prev_state = __get_task_state(curr);
entry->next_pid = wakee->pid;
entry->next_prio = wakee->prio;
entry->next_state = wakee->state;
entry->next_state = __get_task_state(wakee);
entry->next_cpu = task_cpu(wakee);
if (!call_filter_check_discard(call, entry, buffer, event))