[patch 26/44] posix-cpu-timers: Move expiry cache into struct posix_cputimers

Thomas Gleixner
2019-08-19T15:47:38Z

The expiry cache belongs into the posix_cputimers container where the other
cpu timers information is.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/posix-timers.h | 31 ++++++++++++++++++++++++++++++-
include/linux/sched.h | 6 ------
include/linux/sched/signal.h | 3 ---
kernel/fork.c | 25 +++----------------------
kernel/sched/rt.c | 6 ++++--
kernel/time/posix-cpu-timers.c | 38 ++++++++++++++++++++------------------
6 files changed, 57 insertions(+), 52 deletions(-)

--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -62,24 +62,49 @@ static inline int clockid_to_fd(const cl
return ~(clk >> 3);
}

+/*
+ * Alternate field names for struct task_cputime when used on cache
+ * expirations. Will go away soon.
+ */
+#define virt_exp utime
+#define prof_exp stime
+#define sched_exp sum_exec_runtime
+
+#ifdef CONFIG_POSIX_TIMERS
/**
* posix_cputimers - Container for posix CPU timer related data
+ * @cputime_expires: Earliest-expiration cache
* @cpu_timers: List heads to queue posix CPU timers
*
* Used in task_struct and signal_struct
*/
struct posix_cputimers {
+ struct task_cputime cputime_expires;
struct list_head cpu_timers[CPUCLOCK_MAX];
};

static inline void posix_cputimers_init(struct posix_cputimers *pct)
{
+ memset(&pct->cputime_expires, 0, sizeof(pct->cputime_expires));
INIT_LIST_HEAD(&pct->cpu_timers[0]);
INIT_LIST_HEAD(&pct->cpu_timers[1]);
INIT_LIST_HEAD(&pct->cpu_timers[2]);
}

-#ifdef CONFIG_POSIX_TIMERS
+static inline void posix_cputimers_group_init(struct posix_cputimers *pct,
+ u64 cpu_limit)
+{
+ posix_cputimers_init(pct);
+ if (cpu_limit != RLIM_INFINITY)
+ pct->cputime_expires.prof_exp = cpu_limit * NSEC_PER_SEC;
+}
+
+static inline void posix_cputimers_rt_watchdog(struct posix_cputimers *pct,
+ u64 runtime)
+{
+ pct->cputime_expires.sched_exp = runtime;
+}
+
/* Init task static initializer */
#define INIT_CPU_TIMERLISTS(c) { \
LIST_HEAD_INIT(c.cpu_timers[0]), \
@@ -92,7 +117,11 @@ static inline void posix_cputimers_init(
.cpu_timers = INIT_CPU_TIMERLISTS(s.posix_cputimers), \
},
#else
+struct posix_cputimers { };
#define INIT_CPU_TIMERS(s)
+static inline void posix_cputimers_init(struct posix_cputimers *pct) { }
+static inline void posix_cputimers_group_init(struct posix_cputimers *pct,
+ u64 cpu_limit) { }
#endif

#define REQUEUE_PENDING 1
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -246,11 +246,6 @@ struct prev_cputime {
#endif
};

-/* Alternate field names when used on cache expirations: */
-#define virt_exp utime
-#define prof_exp stime
-#define sched_exp sum_exec_runtime
-
enum vtime_state {
/* Task is sleeping or running in a CPU with VTIME inactive: */
VTIME_INACTIVE = 0,
@@ -863,7 +858,6 @@ struct task_struct {
unsigned long maj_flt;

#ifdef CONFIG_POSIX_TIMERS
- struct task_cputime cputime_expires;
struct posix_cputimers posix_cputimers;
#endif

--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -149,9 +149,6 @@ struct signal_struct {
*/
struct thread_group_cputimer cputimer;

- /* Earliest-expiration cache. */
- struct task_cputime cputime_expires;
-
struct posix_cputimers posix_cputimers;
#endif

--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1527,12 +1527,9 @@ static void posix_cpu_timers_init_group(
unsigned long cpu_limit;

cpu_limit = READ_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
- if (cpu_limit != RLIM_INFINITY) {
- sig->cputime_expires.prof_exp = cpu_limit * NSEC_PER_SEC;
+ posix_cputimers_group_init(pct, cpu_limit);
+ if (cpu_limit != RLIM_INFINITY)
sig->cputimer.running = true;
- }
-
- posix_cputimers_init(pct);
}
#else
static inline void posix_cpu_timers_init_group(struct signal_struct *sig) { }
@@ -1638,22 +1635,6 @@ static void rt_mutex_init_task(struct ta
#endif
}

-#ifdef CONFIG_POSIX_TIMERS
-/*
- * Initialize POSIX timer handling for a single task.
- */
-static void posix_cpu_timers_init(struct task_struct *tsk)
-{
- tsk->cputime_expires.prof_exp = 0;
- tsk->cputime_expires.virt_exp = 0;
- tsk->cputime_expires.sched_exp = 0;
-
- posix_cputimers_init(&tsk->posix_cputimers);
-}
-#else
-static inline void posix_cpu_timers_init(struct task_struct *tsk) { }
-#endif
-
static inline void init_task_pid_links(struct task_struct *task)
{
enum pid_type type;
@@ -1932,7 +1913,7 @@ static __latent_entropy struct task_stru
task_io_accounting_init(&p->ioac);
acct_clear_integrals(p);

- posix_cpu_timers_init(p);
+ posix_cputimers_init(&p->posix_cputimers);

p->io_context = NULL;
audit_set_context(p, NULL);
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -2305,8 +2305,10 @@ static void watchdog(struct rq *rq, stru
}

next = DIV_ROUND_UP(min(soft, hard), USEC_PER_SEC/HZ);
- if (p->rt.timeout > next)
- p->cputime_expires.sched_exp = p->se.sum_exec_runtime;
+ if (p->rt.timeout > next) {
+ posix_cputimers_rt_watchdog(&p->posix_cputimers,
+ p->se.sum_exec_runtime);
+ }
}
}
#else
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -22,9 +22,9 @@ static void posix_cpu_timer_rearm(struct

/*
* Called after updating RLIMIT_CPU to run cpu timer and update
- * tsk->signal->cputime_expires expiration cache if necessary. Needs
- * siglock protection since other code may update expiration cache as
- * well.
+ * tsk->signal->posix_cputimers.cputime_expires expiration cache if
+ * necessary. Needs siglock protection since other code may update
+ * expiration cache as well.
*/
void update_rlimit_cpu(struct task_struct *task, unsigned long rlim_new)
{
@@ -447,10 +447,10 @@ static void arm_timer(struct k_itimer *t

if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
head = p->posix_cputimers.cpu_timers;
- cputime_expires = &p->cputime_expires;
+ cputime_expires = &p->posix_cputimers.cputime_expires;
} else {
head = p->signal->posix_cputimers.cpu_timers;
- cputime_expires = &p->signal->cputime_expires;
+ cputime_expires = &p->signal->posix_cputimers.cputime_expires;
}
head += CPUCLOCK_WHICH(timer->it_clock);

@@ -774,7 +774,7 @@ static void check_thread_timers(struct t
struct list_head *firing)
{
struct list_head *timers = tsk->posix_cputimers.cpu_timers;
- struct task_cputime *tsk_expires = &tsk->cputime_expires;
+ struct task_cputime *tsk_expires = &tsk->posix_cputimers.cputime_expires;
u64 expires, stime, utime;
unsigned long soft;

@@ -785,7 +785,7 @@ static void check_thread_timers(struct t
* If cputime_expires is zero, then there are no active
* per thread CPU timers.
*/
- if (task_cputime_zero(&tsk->cputime_expires))
+ if (task_cputime_zero(tsk_expires))
return;

task_cputime(tsk, &utime, &stime);
@@ -954,10 +954,10 @@ static void check_process_timers(struct
prof_expires = x;
}

- sig->cputime_expires.prof_exp = prof_expires;
- sig->cputime_expires.virt_exp = virt_expires;
- sig->cputime_expires.sched_exp = sched_expires;
- if (task_cputime_zero(&sig->cputime_expires))
+ sig->posix_cputimers.cputime_expires.prof_exp = prof_expires;
+ sig->posix_cputimers.cputime_expires.virt_exp = virt_expires;
+ sig->posix_cputimers.cputime_expires.sched_exp = sched_expires;
+ if (task_cputime_zero(&sig->posix_cputimers.cputime_expires))
stop_process_timers(sig);

sig->cputimer.checking_timer = false;
@@ -1058,12 +1058,13 @@ static inline int fastpath_timer_check(s
{
struct signal_struct *sig;

- if (!task_cputime_zero(&tsk->cputime_expires)) {
+ if (!task_cputime_zero(&tsk->posix_cputimers.cputime_expires)) {
struct task_cputime task_sample;

task_cputime(tsk, &task_sample.utime, &task_sample.stime);
task_sample.sum_exec_runtime = tsk->se.sum_exec_runtime;
- if (task_cputime_expired(&task_sample, &tsk->cputime_expires))
+ if (task_cputime_expired(&task_sample,
+ &tsk->posix_cputimers.cputime_expires))
return 1;
}

@@ -1088,7 +1089,8 @@ static inline int fastpath_timer_check(s

sample_cputime_atomic(&group_sample, &sig->cputimer.cputime_atomic);

- if (task_cputime_expired(&group_sample, &sig->cputime_expires))
+ if (task_cputime_expired(&group_sample,
+ &sig->posix_cputimers.cputime_expires))
return 1;
}

@@ -1218,12 +1220,12 @@ void set_process_cpu_timer(struct task_s
*/
switch (clock_idx) {
case CPUCLOCK_PROF:
- if (expires_gt(tsk->signal->cputime_expires.prof_exp, *newval))
- tsk->signal->cputime_expires.prof_exp = *newval;
+ if (expires_gt(tsk->signal->posix_cputimers.cputime_expires.prof_exp, *newval))
+ tsk->signal->posix_cputimers.cputime_expires.prof_exp = *newval;
break;
case CPUCLOCK_VIRT:
- if (expires_gt(tsk->signal->cputime_expires.virt_exp, *newval))
- tsk->signal->cputime_expires.virt_exp = *newval;
+ if (expires_gt(tsk->signal->posix_cputimers.cputime_expires.virt_exp, *newval))
+ tsk->signal->posix_cputimers.cputime_expires.virt_exp = *newval;
break;
}