Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
authorLinus Torvalds <torvalds@linux-foundation.org>
Wed, 23 Sep 2009 16:46:15 +0000 (09:46 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 23 Sep 2009 16:46:15 +0000 (09:46 -0700)
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  itimers: Add tracepoints for itimer
  hrtimer: Add tracepoint for hrtimers
  timers: Add tracepoints for timer_list timers
  cputime: Optimize jiffies_to_cputime(1)
  itimers: Simplify arm_timer() code a bit
  itimers: Fix periodic tics precision
  itimers: Merge ITIMER_VIRT and ITIMER_PROF

Trivial header file include conflicts in kernel/fork.c

13 files changed:
arch/ia64/include/asm/cputime.h
arch/powerpc/include/asm/cputime.h
arch/powerpc/kernel/time.c
arch/s390/include/asm/cputime.h
include/asm-generic/cputime.h
include/linux/sched.h
include/trace/events/timer.h [new file with mode: 0644]
kernel/fork.c
kernel/hrtimer.c
kernel/itimer.c
kernel/posix-cpu-timers.c
kernel/sched.c
kernel/timer.c

index d20b998..7fa8a85 100644 (file)
@@ -30,6 +30,7 @@ typedef u64 cputime_t;
 typedef u64 cputime64_t;
 
 #define cputime_zero                   ((cputime_t)0)
+#define cputime_one_jiffy              jiffies_to_cputime(1)
 #define cputime_max                    ((~((cputime_t)0) >> 1) - 1)
 #define cputime_add(__a, __b)          ((__a) +  (__b))
 #define cputime_sub(__a, __b)          ((__a) -  (__b))
index f42e623..fa19f3f 100644 (file)
@@ -18,6 +18,9 @@
 
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
 #include <asm-generic/cputime.h>
+#ifdef __KERNEL__
+static inline void setup_cputime_one_jiffy(void) { }
+#endif
 #else
 
 #include <linux/types.h>
@@ -48,6 +51,11 @@ typedef u64 cputime64_t;
 
 #ifdef __KERNEL__
 
+/*
+ * One jiffy in timebase units computed during initialization
+ */
+extern cputime_t cputime_one_jiffy;
+
 /*
  * Convert cputime <-> jiffies
  */
@@ -89,6 +97,11 @@ static inline cputime_t jiffies_to_cputime(const unsigned long jif)
        return ct;
 }
 
+static inline void setup_cputime_one_jiffy(void)
+{
+       cputime_one_jiffy = jiffies_to_cputime(1);
+}
+
 static inline cputime64_t jiffies64_to_cputime64(const u64 jif)
 {
        cputime_t ct;
index df45a74..92dc844 100644 (file)
@@ -193,6 +193,8 @@ EXPORT_SYMBOL(__cputime_clockt_factor);
 DEFINE_PER_CPU(unsigned long, cputime_last_delta);
 DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta);
 
+cputime_t cputime_one_jiffy;
+
 static void calc_cputime_factors(void)
 {
        struct div_result res;
@@ -501,6 +503,7 @@ static int __init iSeries_tb_recal(void)
                                tb_to_xs = divres.result_low;
                                vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
                                vdso_data->tb_to_xs = tb_to_xs;
+                               setup_cputime_one_jiffy();
                        }
                        else {
                                printk( "Titan recalibrate: FAILED (difference > 4 percent)\n"
@@ -960,6 +963,7 @@ void __init time_init(void)
        tb_ticks_per_usec = ppc_tb_freq / 1000000;
        tb_to_us = mulhwu_scale_factor(ppc_tb_freq, 1000000);
        calc_cputime_factors();
+       setup_cputime_one_jiffy();
 
        /*
         * Calculate the length of each tick in ns.  It will not be
index 7a3817a..24b1244 100644 (file)
@@ -42,6 +42,7 @@ __div(unsigned long long n, unsigned int base)
 #endif /* __s390x__ */
 
 #define cputime_zero                   (0ULL)
+#define cputime_one_jiffy              jiffies_to_cputime(1)
 #define cputime_max                    ((~0UL >> 1) - 1)
 #define cputime_add(__a, __b)          ((__a) +  (__b))
 #define cputime_sub(__a, __b)          ((__a) -  (__b))
index 1c1fa42..ca0f239 100644 (file)
@@ -7,6 +7,7 @@
 typedef unsigned long cputime_t;
 
 #define cputime_zero                   (0UL)
+#define cputime_one_jiffy              jiffies_to_cputime(1)
 #define cputime_max                    ((~0UL >> 1) - 1)
 #define cputime_add(__a, __b)          ((__a) +  (__b))
 #define cputime_sub(__a, __b)          ((__a) -  (__b))
index 3cbc6c0..cbf2a3b 100644 (file)
@@ -493,6 +493,13 @@ struct pacct_struct {
        unsigned long           ac_minflt, ac_majflt;
 };
 
+struct cpu_itimer {
+       cputime_t expires;
+       cputime_t incr;
+       u32 error;
+       u32 incr_error;
+};
+
 /**
  * struct task_cputime - collected CPU time counts
  * @utime:             time spent in user mode, in &cputime_t units
@@ -587,9 +594,12 @@ struct signal_struct {
        struct pid *leader_pid;
        ktime_t it_real_incr;
 
-       /* ITIMER_PROF and ITIMER_VIRTUAL timers for the process */
-       cputime_t it_prof_expires, it_virt_expires;
-       cputime_t it_prof_incr, it_virt_incr;
+       /*
+        * ITIMER_PROF and ITIMER_VIRTUAL timers for the process, we use
+        * CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing array as these
+        * values are defined to 0 and 1 respectively
+        */
+       struct cpu_itimer it[2];
 
        /*
         * Thread group totals for process CPU timers.
diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h
new file mode 100644 (file)
index 0000000..1844c48
--- /dev/null
@@ -0,0 +1,342 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM timer
+
+#if !defined(_TRACE_TIMER_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_TIMER_H
+
+#include <linux/tracepoint.h>
+#include <linux/hrtimer.h>
+#include <linux/timer.h>
+
+/**
+ * timer_init - called when the timer is initialized
+ * @timer:     pointer to struct timer_list
+ */
+TRACE_EVENT(timer_init,
+
+       TP_PROTO(struct timer_list *timer),
+
+       TP_ARGS(timer),
+
+       TP_STRUCT__entry(
+               __field( void *,        timer   )
+       ),
+
+       TP_fast_assign(
+               __entry->timer  = timer;
+       ),
+
+       TP_printk("timer %p", __entry->timer)
+);
+
+/**
+ * timer_start - called when the timer is started
+ * @timer:     pointer to struct timer_list
+ * @expires:   the timers expiry time
+ */
+TRACE_EVENT(timer_start,
+
+       TP_PROTO(struct timer_list *timer, unsigned long expires),
+
+       TP_ARGS(timer, expires),
+
+       TP_STRUCT__entry(
+               __field( void *,        timer           )
+               __field( void *,        function        )
+               __field( unsigned long, expires         )
+               __field( unsigned long, now             )
+       ),
+
+       TP_fast_assign(
+               __entry->timer          = timer;
+               __entry->function       = timer->function;
+               __entry->expires        = expires;
+               __entry->now            = jiffies;
+       ),
+
+       TP_printk("timer %p: func %pf, expires %lu, timeout %ld",
+                 __entry->timer, __entry->function, __entry->expires,
+                 (long)__entry->expires - __entry->now)
+);
+
+/**
+ * timer_expire_entry - called immediately before the timer callback
+ * @timer:     pointer to struct timer_list
+ *
+ * Allows to determine the timer latency.
+ */
+TRACE_EVENT(timer_expire_entry,
+
+       TP_PROTO(struct timer_list *timer),
+
+       TP_ARGS(timer),
+
+       TP_STRUCT__entry(
+               __field( void *,        timer   )
+               __field( unsigned long, now     )
+       ),
+
+       TP_fast_assign(
+               __entry->timer          = timer;
+               __entry->now            = jiffies;
+       ),
+
+       TP_printk("timer %p: now %lu", __entry->timer, __entry->now)
+);
+
+/**
+ * timer_expire_exit - called immediately after the timer callback returns
+ * @timer:     pointer to struct timer_list
+ *
+ * When used in combination with the timer_expire_entry tracepoint we can
+ * determine the runtime of the timer callback function.
+ *
+ * NOTE: Do NOT derefernce timer in TP_fast_assign. The pointer might
+ * be invalid. We solely track the pointer.
+ */
+TRACE_EVENT(timer_expire_exit,
+
+       TP_PROTO(struct timer_list *timer),
+
+       TP_ARGS(timer),
+
+       TP_STRUCT__entry(
+               __field(void *, timer   )
+       ),
+
+       TP_fast_assign(
+               __entry->timer  = timer;
+       ),
+
+       TP_printk("timer %p", __entry->timer)
+);
+
+/**
+ * timer_cancel - called when the timer is canceled
+ * @timer:     pointer to struct timer_list
+ */
+TRACE_EVENT(timer_cancel,
+
+       TP_PROTO(struct timer_list *timer),
+
+       TP_ARGS(timer),
+
+       TP_STRUCT__entry(
+               __field( void *,        timer   )
+       ),
+
+       TP_fast_assign(
+               __entry->timer  = timer;
+       ),
+
+       TP_printk("timer %p", __entry->timer)
+);
+
+/**
+ * hrtimer_init - called when the hrtimer is initialized
+ * @timer:     pointer to struct hrtimer
+ * @clockid:   the hrtimers clock
+ * @mode:      the hrtimers mode
+ */
+TRACE_EVENT(hrtimer_init,
+
+       TP_PROTO(struct hrtimer *timer, clockid_t clockid,
+                enum hrtimer_mode mode),
+
+       TP_ARGS(timer, clockid, mode),
+
+       TP_STRUCT__entry(
+               __field( void *,                timer           )
+               __field( clockid_t,             clockid         )
+               __field( enum hrtimer_mode,     mode            )
+       ),
+
+       TP_fast_assign(
+               __entry->timer          = timer;
+               __entry->clockid        = clockid;
+               __entry->mode           = mode;
+       ),
+
+       TP_printk("hrtimer %p, clockid %s, mode %s", __entry->timer,
+                 __entry->clockid == CLOCK_REALTIME ?
+                       "CLOCK_REALTIME" : "CLOCK_MONOTONIC",
+                 __entry->mode == HRTIMER_MODE_ABS ?
+                       "HRTIMER_MODE_ABS" : "HRTIMER_MODE_REL")
+);
+
+/**
+ * hrtimer_start - called when the hrtimer is started
+ * @timer: pointer to struct hrtimer
+ */
+TRACE_EVENT(hrtimer_start,
+
+       TP_PROTO(struct hrtimer *timer),
+
+       TP_ARGS(timer),
+
+       TP_STRUCT__entry(
+               __field( void *,        timer           )
+               __field( void *,        function        )
+               __field( s64,           expires         )
+               __field( s64,           softexpires     )
+       ),
+
+       TP_fast_assign(
+               __entry->timer          = timer;
+               __entry->function       = timer->function;
+               __entry->expires        = hrtimer_get_expires(timer).tv64;
+               __entry->softexpires    = hrtimer_get_softexpires(timer).tv64;
+       ),
+
+       TP_printk("hrtimer %p, func %pf, expires %llu, softexpires %llu",
+                 __entry->timer, __entry->function,
+                 (unsigned long long)ktime_to_ns((ktime_t) {
+                                 .tv64 = __entry->expires }),
+                 (unsigned long long)ktime_to_ns((ktime_t) {
+                                 .tv64 = __entry->softexpires }))
+);
+
+/**
+ * htimmer_expire_entry - called immediately before the hrtimer callback
+ * @timer:     pointer to struct hrtimer
+ * @now:       pointer to variable which contains current time of the
+ *             timers base.
+ *
+ * Allows to determine the timer latency.
+ */
+TRACE_EVENT(hrtimer_expire_entry,
+
+       TP_PROTO(struct hrtimer *timer, ktime_t *now),
+
+       TP_ARGS(timer, now),
+
+       TP_STRUCT__entry(
+               __field( void *,        timer   )
+               __field( s64,           now     )
+       ),
+
+       TP_fast_assign(
+               __entry->timer  = timer;
+               __entry->now    = now->tv64;
+       ),
+
+       TP_printk("hrtimer %p, now %llu", __entry->timer,
+                 (unsigned long long)ktime_to_ns((ktime_t) {
+                                 .tv64 = __entry->now }))
+ );
+
+/**
+ * hrtimer_expire_exit - called immediately after the hrtimer callback returns
+ * @timer:     pointer to struct hrtimer
+ *
+ * When used in combination with the hrtimer_expire_entry tracepoint we can
+ * determine the runtime of the callback function.
+ */
+TRACE_EVENT(hrtimer_expire_exit,
+
+       TP_PROTO(struct hrtimer *timer),
+
+       TP_ARGS(timer),
+
+       TP_STRUCT__entry(
+               __field( void *,        timer   )
+       ),
+
+       TP_fast_assign(
+               __entry->timer  = timer;
+       ),
+
+       TP_printk("hrtimer %p", __entry->timer)
+);
+
+/**
+ * hrtimer_cancel - called when the hrtimer is canceled
+ * @timer:     pointer to struct hrtimer
+ */
+TRACE_EVENT(hrtimer_cancel,
+
+       TP_PROTO(struct hrtimer *timer),
+
+       TP_ARGS(timer),
+
+       TP_STRUCT__entry(
+               __field( void *,        timer   )
+       ),
+
+       TP_fast_assign(
+               __entry->timer  = timer;
+       ),
+
+       TP_printk("hrtimer %p", __entry->timer)
+);
+
+/**
+ * itimer_state - called when itimer is started or canceled
+ * @which:     name of the interval timer
+ * @value:     the itimers value, itimer is canceled if value->it_value is
+ *             zero, otherwise it is started
+ * @expires:   the itimers expiry time
+ */
+TRACE_EVENT(itimer_state,
+
+       TP_PROTO(int which, const struct itimerval *const value,
+                cputime_t expires),
+
+       TP_ARGS(which, value, expires),
+
+       TP_STRUCT__entry(
+               __field(        int,            which           )
+               __field(        cputime_t,      expires         )
+               __field(        long,           value_sec       )
+               __field(        long,           value_usec      )
+               __field(        long,           interval_sec    )
+               __field(        long,           interval_usec   )
+       ),
+
+       TP_fast_assign(
+               __entry->which          = which;
+               __entry->expires        = expires;
+               __entry->value_sec      = value->it_value.tv_sec;
+               __entry->value_usec     = value->it_value.tv_usec;
+               __entry->interval_sec   = value->it_interval.tv_sec;
+               __entry->interval_usec  = value->it_interval.tv_usec;
+       ),
+
+       TP_printk("which %d, expires %lu, it_value %lu.%lu, it_interval %lu.%lu",
+                 __entry->which, __entry->expires,
+                 __entry->value_sec, __entry->value_usec,
+                 __entry->interval_sec, __entry->interval_usec)
+);
+
+/**
+ * itimer_expire - called when itimer expires
+ * @which:     type of the interval timer
+ * @pid:       pid of the process which owns the timer
+ * @now:       current time, used to calculate the latency of itimer
+ */
+TRACE_EVENT(itimer_expire,
+
+       TP_PROTO(int which, struct pid *pid, cputime_t now),
+
+       TP_ARGS(which, pid, now),
+
+       TP_STRUCT__entry(
+               __field( int ,          which   )
+               __field( pid_t,         pid     )
+               __field( cputime_t,     now     )
+       ),
+
+       TP_fast_assign(
+               __entry->which  = which;
+               __entry->now    = now;
+               __entry->pid    = pid_nr(pid);
+       ),
+
+           TP_printk("which %d, pid %d, now %lu", __entry->which,
+                     (int) __entry->pid, __entry->now)
+);
+
+#endif /*  _TRACE_TIMER_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
index 8f45b0e..51ad0b0 100644 (file)
@@ -63,6 +63,7 @@
 #include <linux/fs_struct.h>
 #include <linux/magic.h>
 #include <linux/perf_event.h>
+#include <linux/posix-timers.h>
 
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
@@ -805,10 +806,10 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig)
        thread_group_cputime_init(sig);
 
        /* Expiration times and increments. */
-       sig->it_virt_expires = cputime_zero;
-       sig->it_virt_incr = cputime_zero;
-       sig->it_prof_expires = cputime_zero;
-       sig->it_prof_incr = cputime_zero;
+       sig->it[CPUCLOCK_PROF].expires = cputime_zero;
+       sig->it[CPUCLOCK_PROF].incr = cputime_zero;
+       sig->it[CPUCLOCK_VIRT].expires = cputime_zero;
+       sig->it[CPUCLOCK_VIRT].incr = cputime_zero;
 
        /* Cached expiration times. */
        sig->cputime_expires.prof_exp = cputime_zero;
index c03f221..e5d98ce 100644 (file)
@@ -48,6 +48,8 @@
 
 #include <asm/uaccess.h>
 
+#include <trace/events/timer.h>
+
 /*
  * The timer bases:
  *
@@ -442,6 +444,26 @@ static inline void debug_hrtimer_activate(struct hrtimer *timer) { }
 static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
 #endif
 
+static inline void
+debug_init(struct hrtimer *timer, clockid_t clockid,
+          enum hrtimer_mode mode)
+{
+       debug_hrtimer_init(timer);
+       trace_hrtimer_init(timer, clockid, mode);
+}
+
+static inline void debug_activate(struct hrtimer *timer)
+{
+       debug_hrtimer_activate(timer);
+       trace_hrtimer_start(timer);
+}
+
+static inline void debug_deactivate(struct hrtimer *timer)
+{
+       debug_hrtimer_deactivate(timer);
+       trace_hrtimer_cancel(timer);
+}
+
 /* High resolution timer related functions */
 #ifdef CONFIG_HIGH_RES_TIMERS
 
@@ -798,7 +820,7 @@ static int enqueue_hrtimer(struct hrtimer *timer,
        struct hrtimer *entry;
        int leftmost = 1;
 
-       debug_hrtimer_activate(timer);
+       debug_activate(timer);
 
        /*
         * Find the right place in the rbtree:
@@ -884,7 +906,7 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
                 * reprogramming happens in the interrupt handler. This is a
                 * rare case and less expensive than a smp call.
                 */
-               debug_hrtimer_deactivate(timer);
+               debug_deactivate(timer);
                timer_stats_hrtimer_clear_start_info(timer);
                reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
                __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE,
@@ -1117,7 +1139,7 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
                  enum hrtimer_mode mode)
 {
-       debug_hrtimer_init(timer);
+       debug_init(timer, clock_id, mode);
        __hrtimer_init(timer, clock_id, mode);
 }
 EXPORT_SYMBOL_GPL(hrtimer_init);
@@ -1141,7 +1163,7 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
 }
 EXPORT_SYMBOL_GPL(hrtimer_get_res);
 
-static void __run_hrtimer(struct hrtimer *timer)
+static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
 {
        struct hrtimer_clock_base *base = timer->base;
        struct hrtimer_cpu_base *cpu_base = base->cpu_base;
@@ -1150,7 +1172,7 @@ static void __run_hrtimer(struct hrtimer *timer)
 
        WARN_ON(!irqs_disabled());
 
-       debug_hrtimer_deactivate(timer);
+       debug_deactivate(timer);
        __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
        timer_stats_account_hrtimer(timer);
        fn = timer->function;
@@ -1161,7 +1183,9 @@ static void __run_hrtimer(struct hrtimer *timer)
         * the timer base.
         */
        spin_unlock(&cpu_base->lock);
+       trace_hrtimer_expire_entry(timer, now);
        restart = fn(timer);
+       trace_hrtimer_expire_exit(timer);
        spin_lock(&cpu_base->lock);
 
        /*
@@ -1272,7 +1296,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
                                break;
                        }
 
-                       __run_hrtimer(timer);
+                       __run_hrtimer(timer, &basenow);
                }
                base++;
        }
@@ -1394,7 +1418,7 @@ void hrtimer_run_queues(void)
                                        hrtimer_get_expires_tv64(timer))
                                break;
 
-                       __run_hrtimer(timer);
+                       __run_hrtimer(timer, &base->softirq_time);
                }
                spin_unlock(&cpu_base->lock);
        }
@@ -1571,7 +1595,7 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
        while ((node = rb_first(&old_base->active))) {
                timer = rb_entry(node, struct hrtimer, node);
                BUG_ON(hrtimer_callback_running(timer));
-               debug_hrtimer_deactivate(timer);
+               debug_deactivate(timer);
 
                /*
                 * Mark it as STATE_MIGRATE not INACTIVE otherwise the
index 58762f7..b03451e 100644 (file)
@@ -12,6 +12,7 @@
 #include <linux/time.h>
 #include <linux/posix-timers.h>
 #include <linux/hrtimer.h>
+#include <trace/events/timer.h>
 
 #include <asm/uaccess.h>
 
@@ -41,10 +42,43 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer)
        return ktime_to_timeval(rem);
 }
 
+static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
+                          struct itimerval *const value)
+{
+       cputime_t cval, cinterval;
+       struct cpu_itimer *it = &tsk->signal->it[clock_id];
+
+       spin_lock_irq(&tsk->sighand->siglock);
+
+       cval = it->expires;
+       cinterval = it->incr;
+       if (!cputime_eq(cval, cputime_zero)) {
+               struct task_cputime cputime;
+               cputime_t t;
+
+               thread_group_cputimer(tsk, &cputime);
+               if (clock_id == CPUCLOCK_PROF)
+                       t = cputime_add(cputime.utime, cputime.stime);
+               else
+                       /* CPUCLOCK_VIRT */
+                       t = cputime.utime;
+
+               if (cputime_le(cval, t))
+                       /* about to fire */
+                       cval = cputime_one_jiffy;
+               else
+                       cval = cputime_sub(cval, t);
+       }
+
+       spin_unlock_irq(&tsk->sighand->siglock);
+
+       cputime_to_timeval(cval, &value->it_value);
+       cputime_to_timeval(cinterval, &value->it_interval);
+}
+
 int do_getitimer(int which, struct itimerval *value)
 {
        struct task_struct *tsk = current;
-       cputime_t cinterval, cval;
 
        switch (which) {
        case ITIMER_REAL:
@@ -55,44 +89,10 @@ int do_getitimer(int which, struct itimerval *value)
                spin_unlock_irq(&tsk->sighand->siglock);
                break;
        case ITIMER_VIRTUAL:
-               spin_lock_irq(&tsk->sighand->siglock);
-               cval = tsk->signal->it_virt_expires;
-               cinterval = tsk->signal->it_virt_incr;
-               if (!cputime_eq(cval, cputime_zero)) {
-                       struct task_cputime cputime;
-                       cputime_t utime;
-
-                       thread_group_cputimer(tsk, &cputime);
-                       utime = cputime.utime;
-                       if (cputime_le(cval, utime)) { /* about to fire */
-                               cval = jiffies_to_cputime(1);
-                       } else {
-                               cval = cputime_sub(cval, utime);
-                       }
-               }
-               spin_unlock_irq(&tsk->sighand->siglock);
-               cputime_to_timeval(cval, &value->it_value);
-               cputime_to_timeval(cinterval, &value->it_interval);
+               get_cpu_itimer(tsk, CPUCLOCK_VIRT, value);
                break;
        case ITIMER_PROF:
-               spin_lock_irq(&tsk->sighand->siglock);
-               cval = tsk->signal->it_prof_expires;
-               cinterval = tsk->signal->it_prof_incr;
-               if (!cputime_eq(cval, cputime_zero)) {
-                       struct task_cputime times;
-                       cputime_t ptime;
-
-                       thread_group_cputimer(tsk, &times);
-                       ptime = cputime_add(times.utime, times.stime);
-                       if (cputime_le(cval, ptime)) { /* about to fire */
-                               cval = jiffies_to_cputime(1);
-                       } else {
-                               cval = cputime_sub(cval, ptime);
-                       }
-               }
-               spin_unlock_irq(&tsk->sighand->siglock);
-               cputime_to_timeval(cval, &value->it_value);
-               cputime_to_timeval(cinterval, &value->it_interval);
+               get_cpu_itimer(tsk, CPUCLOCK_PROF, value);
                break;
        default:
                return(-EINVAL);
@@ -123,11 +123,62 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer)
        struct signal_struct *sig =
                container_of(timer, struct signal_struct, real_timer);
 
+       trace_itimer_expire(ITIMER_REAL, sig->leader_pid, 0);
        kill_pid_info(SIGALRM, SEND_SIG_PRIV, sig->leader_pid);
 
        return HRTIMER_NORESTART;
 }
 
+static inline u32 cputime_sub_ns(cputime_t ct, s64 real_ns)
+{
+       struct timespec ts;
+       s64 cpu_ns;
+
+       cputime_to_timespec(ct, &ts);
+       cpu_ns = timespec_to_ns(&ts);
+
+       return (cpu_ns <= real_ns) ? 0 : cpu_ns - real_ns;
+}
+
+static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
+                          const struct itimerval *const value,
+                          struct itimerval *const ovalue)
+{
+       cputime_t cval, nval, cinterval, ninterval;
+       s64 ns_ninterval, ns_nval;
+       struct cpu_itimer *it = &tsk->signal->it[clock_id];
+
+       nval = timeval_to_cputime(&value->it_value);
+       ns_nval = timeval_to_ns(&value->it_value);
+       ninterval = timeval_to_cputime(&value->it_interval);
+       ns_ninterval = timeval_to_ns(&value->it_interval);
+
+       it->incr_error = cputime_sub_ns(ninterval, ns_ninterval);
+       it->error = cputime_sub_ns(nval, ns_nval);
+
+       spin_lock_irq(&tsk->sighand->siglock);
+
+       cval = it->expires;
+       cinterval = it->incr;
+       if (!cputime_eq(cval, cputime_zero) ||
+           !cputime_eq(nval, cputime_zero)) {
+               if (cputime_gt(nval, cputime_zero))
+                       nval = cputime_add(nval, cputime_one_jiffy);
+               set_process_cpu_timer(tsk, clock_id, &nval, &cval);
+       }
+       it->expires = nval;
+       it->incr = ninterval;
+       trace_itimer_state(clock_id == CPUCLOCK_VIRT ?
+                          ITIMER_VIRTUAL : ITIMER_PROF, value, nval);
+
+       spin_unlock_irq(&tsk->sighand->siglock);
+
+       if (ovalue) {
+               cputime_to_timeval(cval, &ovalue->it_value);
+               cputime_to_timeval(cinterval, &ovalue->it_interval);
+       }
+}
+
 /*
  * Returns true if the timeval is in canonical form
  */
@@ -139,7 +190,6 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
        struct task_struct *tsk = current;
        struct hrtimer *timer;
        ktime_t expires;
-       cputime_t cval, cinterval, nval, ninterval;
 
        /*
         * Validate the timevals in value.
@@ -171,51 +221,14 @@ again:
                } else
                        tsk->signal->it_real_incr.tv64 = 0;
 
+               trace_itimer_state(ITIMER_REAL, value, 0);
                spin_unlock_irq(&tsk->sighand->siglock);
                break;
        case ITIMER_VIRTUAL:
-               nval = timeval_to_cputime(&value->it_value);
-               ninterval = timeval_to_cputime(&value->it_interval);
-               spin_lock_irq(&tsk->sighand->siglock);
-               cval = tsk->signal->it_virt_expires;
-               cinterval = tsk->signal->it_virt_incr;
-               if (!cputime_eq(cval, cputime_zero) ||
-                   !cputime_eq(nval, cputime_zero)) {
-                       if (cputime_gt(nval, cputime_zero))
-                               nval = cputime_add(nval,
-                                                  jiffies_to_cputime(1));
-                       set_process_cpu_timer(tsk, CPUCLOCK_VIRT,
-                                             &nval, &cval);
-               }
-               tsk->signal->it_virt_expires = nval;
-               tsk->signal->it_virt_incr = ninterval;
-               spin_unlock_irq(&tsk->sighand->siglock);
-               if (ovalue) {
-                       cputime_to_timeval(cval, &ovalue->it_value);
-                       cputime_to_timeval(cinterval, &ovalue->it_interval);
-               }
+               set_cpu_itimer(tsk, CPUCLOCK_VIRT, value, ovalue);
                break;
        case ITIMER_PROF:
-               nval = timeval_to_cputime(&value->it_value);
-               ninterval = timeval_to_cputime(&value->it_interval);
-               spin_lock_irq(&tsk->sighand->siglock);
-               cval = tsk->signal->it_prof_expires;
-               cinterval = tsk->signal->it_prof_incr;
-               if (!cputime_eq(cval, cputime_zero) ||
-                   !cputime_eq(nval, cputime_zero)) {
-                       if (cputime_gt(nval, cputime_zero))
-                               nval = cputime_add(nval,
-                                                  jiffies_to_cputime(1));
-                       set_process_cpu_timer(tsk, CPUCLOCK_PROF,
-                                             &nval, &cval);
-               }
-               tsk->signal->it_prof_expires = nval;
-               tsk->signal->it_prof_incr = ninterval;
-               spin_unlock_irq(&tsk->sighand->siglock);
-               if (ovalue) {
-                       cputime_to_timeval(cval, &ovalue->it_value);
-                       cputime_to_timeval(cinterval, &ovalue->it_interval);
-               }
+               set_cpu_itimer(tsk, CPUCLOCK_PROF, value, ovalue);
                break;
        default:
                return -EINVAL;
index e33a21c..5c9dc22 100644 (file)
@@ -8,17 +8,18 @@
 #include <linux/math64.h>
 #include <asm/uaccess.h>
 #include <linux/kernel_stat.h>
+#include <trace/events/timer.h>
 
 /*
  * Called after updating RLIMIT_CPU to set timer expiration if necessary.
  */
 void update_rlimit_cpu(unsigned long rlim_new)
 {
-       cputime_t cputime;
+       cputime_t cputime = secs_to_cputime(rlim_new);
+       struct signal_struct *const sig = current->signal;
 
-       cputime = secs_to_cputime(rlim_new);
-       if (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
-           cputime_gt(current->signal->it_prof_expires, cputime)) {
+       if (cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) ||
+           cputime_gt(sig->it[CPUCLOCK_PROF].expires, cputime)) {
                spin_lock_irq(&current->sighand->siglock);
                set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
                spin_unlock_irq(&current->sighand->siglock);
@@ -542,6 +543,17 @@ static void clear_dead_task(struct k_itimer *timer, union cpu_time_count now)
                                             now);
 }
 
+static inline int expires_gt(cputime_t expires, cputime_t new_exp)
+{
+       return cputime_eq(expires, cputime_zero) ||
+              cputime_gt(expires, new_exp);
+}
+
+static inline int expires_le(cputime_t expires, cputime_t new_exp)
+{
+       return !cputime_eq(expires, cputime_zero) &&
+              cputime_le(expires, new_exp);
+}
 /*
  * Insert the timer on the appropriate list before any timers that
  * expire later.  This must be called with the tasklist_lock held
@@ -586,34 +598,32 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
                 */
 
                if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
+                       union cpu_time_count *exp = &nt->expires;
+
                        switch (CPUCLOCK_WHICH(timer->it_clock)) {
                        default:
                                BUG();
                        case CPUCLOCK_PROF:
-                               if (cputime_eq(p->cputime_expires.prof_exp,
-                                              cputime_zero) ||
-                                   cputime_gt(p->cputime_expires.prof_exp,
-                                              nt->expires.cpu))
-                                       p->cputime_expires.prof_exp =
-                                               nt->expires.cpu;
+                               if (expires_gt(p->cputime_expires.prof_exp,
+                                              exp->cpu))
+                                       p->cputime_expires.prof_exp = exp->cpu;
                                break;
                        case CPUCLOCK_VIRT:
-                               if (cputime_eq(p->cputime_expires.virt_exp,
-                                              cputime_zero) ||
-                                   cputime_gt(p->cputime_expires.virt_exp,
-                                              nt->expires.cpu))
-                                       p->cputime_expires.virt_exp =
-                                               nt->expires.cpu;
+                               if (expires_gt(p->cputime_expires.virt_exp,
+                                              exp->cpu))
+                                       p->cputime_expires.virt_exp = exp->cpu;
                                break;
                        case CPUCLOCK_SCHED:
                                if (p->cputime_expires.sched_exp == 0 ||
-                                   p->cputime_expires.sched_exp >
-                                                       nt->expires.sched)
+                                   p->cputime_expires.sched_exp > exp->sched)
                                        p->cputime_expires.sched_exp =
-                                               nt->expires.sched;
+                                                               exp->sched;
                                break;
                        }
                } else {
+                       struct signal_struct *const sig = p->signal;
+                       union cpu_time_count *exp = &timer->it.cpu.expires;
+
                        /*
                         * For a process timer, set the cached expiration time.
                         */
@@ -621,30 +631,23 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now)
                        default:
                                BUG();
                        case CPUCLOCK_VIRT:
-                               if (!cputime_eq(p->signal->it_virt_expires,
-                                               cputime_zero) &&
-                                   cputime_lt(p->signal->it_virt_expires,
-                                              timer->it.cpu.expires.cpu))
+                               if (expires_le(sig->it[CPUCLOCK_VIRT].expires,
+                                              exp->cpu))
                                        break;
-                               p->signal->cputime_expires.virt_exp =
-                                       timer->it.cpu.expires.cpu;
+                               sig->cputime_expires.virt_exp = exp->cpu;
                                break;
                        case CPUCLOCK_PROF:
-                               if (!cputime_eq(p->signal->it_prof_expires,
-                                               cputime_zero) &&
-                                   cputime_lt(p->signal->it_prof_expires,
-                                              timer->it.cpu.expires.cpu))
+                               if (expires_le(sig->it[CPUCLOCK_PROF].expires,
+                                              exp->cpu))
                                        break;
-                               i = p->signal->rlim[RLIMIT_CPU].rlim_cur;
+                               i = sig->rlim[RLIMIT_CPU].rlim_cur;
                                if (i != RLIM_INFINITY &&
-                                   i <= cputime_to_secs(timer->it.cpu.expires.cpu))
+                                   i <= cputime_to_secs(exp->cpu))
                                        break;
-                               p->signal->cputime_expires.prof_exp =
-                                       timer->it.cpu.expires.cpu;
+                               sig->cputime_expires.prof_exp = exp->cpu;
                                break;
                        case CPUCLOCK_SCHED:
-                               p->signal->cputime_expires.sched_exp =
-                                       timer->it.cpu.expires.sched;
+                               sig->cputime_expires.sched_exp = exp->sched;
                                break;
                        }
                }
@@ -1071,6 +1074,40 @@ static void stop_process_timers(struct task_struct *tsk)
        spin_unlock_irqrestore(&cputimer->lock, flags);
 }
 
+static u32 onecputick;
+
+static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it,
+                            cputime_t *expires, cputime_t cur_time, int signo)
+{
+       if (cputime_eq(it->expires, cputime_zero))
+               return;
+
+       if (cputime_ge(cur_time, it->expires)) {
+               if (!cputime_eq(it->incr, cputime_zero)) {
+                       it->expires = cputime_add(it->expires, it->incr);
+                       it->error += it->incr_error;
+                       if (it->error >= onecputick) {
+                               it->expires = cputime_sub(it->expires,
+                                                         cputime_one_jiffy);
+                               it->error -= onecputick;
+                       }
+               } else {
+                       it->expires = cputime_zero;
+               }
+
+               trace_itimer_expire(signo == SIGPROF ?
+                                   ITIMER_PROF : ITIMER_VIRTUAL,
+                                   tsk->signal->leader_pid, cur_time);
+               __group_send_sig_info(signo, SEND_SIG_PRIV, tsk);
+       }
+
+       if (!cputime_eq(it->expires, cputime_zero) &&
+           (cputime_eq(*expires, cputime_zero) ||
+            cputime_lt(it->expires, *expires))) {
+               *expires = it->expires;
+       }
+}
+
 /*
  * Check for any per-thread CPU timers that have fired and move them
  * off the tsk->*_timers list onto the firing list.  Per-thread timers
@@ -1090,10 +1127,10 @@ static void check_process_timers(struct task_struct *tsk,
         * Don't sample the current process CPU clocks if there are no timers.
         */
        if (list_empty(&timers[CPUCLOCK_PROF]) &&
-           cputime_eq(sig->it_prof_expires, cputime_zero) &&
+           cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) &&
            sig->rlim[RLIMIT_CPU].rlim_cur == RLIM_INFINITY &&
            list_empty(&timers[CPUCLOCK_VIRT]) &&
-           cputime_eq(sig->it_virt_expires, cputime_zero) &&
+           cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) &&
            list_empty(&timers[CPUCLOCK_SCHED])) {
                stop_process_timers(tsk);
                return;
@@ -1153,38 +1190,11 @@ static void check_process_timers(struct task_struct *tsk,
        /*
         * Check for the special case process timers.
         */
-       if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
-               if (cputime_ge(ptime, sig->it_prof_expires)) {
-                       /* ITIMER_PROF fires and reloads.  */
-                       sig->it_prof_expires = sig->it_prof_incr;
-                       if (!cputime_eq(sig->it_prof_expires, cputime_zero)) {
-                               sig->it_prof_expires = cputime_add(
-                                       sig->it_prof_expires, ptime);
-                       }
-                       __group_send_sig_info(SIGPROF, SEND_SIG_PRIV, tsk);
-               }
-               if (!cputime_eq(sig->it_prof_expires, cputime_zero) &&
-                   (cputime_eq(prof_expires, cputime_zero) ||
-                    cputime_lt(sig->it_prof_expires, prof_expires))) {
-                       prof_expires = sig->it_prof_expires;
-               }
-       }
-       if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
-               if (cputime_ge(utime, sig->it_virt_expires)) {
-                       /* ITIMER_VIRTUAL fires and reloads.  */
-                       sig->it_virt_expires = sig->it_virt_incr;
-                       if (!cputime_eq(sig->it_virt_expires, cputime_zero)) {
-                               sig->it_virt_expires = cputime_add(
-                                       sig->it_virt_expires, utime);
-                       }
-                       __group_send_sig_info(SIGVTALRM, SEND_SIG_PRIV, tsk);
-               }
-               if (!cputime_eq(sig->it_virt_expires, cputime_zero) &&
-                   (cputime_eq(virt_expires, cputime_zero) ||
-                    cputime_lt(sig->it_virt_expires, virt_expires))) {
-                       virt_expires = sig->it_virt_expires;
-               }
-       }
+       check_cpu_itimer(tsk, &sig->it[CPUCLOCK_PROF], &prof_expires, ptime,
+                        SIGPROF);
+       check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
+                        SIGVTALRM);
+
        if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
                unsigned long psecs = cputime_to_secs(ptime);
                cputime_t x;
@@ -1457,7 +1467,7 @@ void set_process_cpu_timer(struct task_struct *tsk, unsigned int clock_idx,
                if (!cputime_eq(*oldval, cputime_zero)) {
                        if (cputime_le(*oldval, now.cpu)) {
                                /* Just about to fire. */
-                               *oldval = jiffies_to_cputime(1);
+                               *oldval = cputime_one_jiffy;
                        } else {
                                *oldval = cputime_sub(*oldval, now.cpu);
                        }
@@ -1703,10 +1713,15 @@ static __init int init_posix_cpu_timers(void)
                .nsleep = thread_cpu_nsleep,
                .nsleep_restart = thread_cpu_nsleep_restart,
        };
+       struct timespec ts;
 
        register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process);
        register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread);
 
+       cputime_to_timespec(cputime_one_jiffy, &ts);
+       onecputick = ts.tv_nsec;
+       WARN_ON(ts.tv_sec != 0);
+
        return 0;
 }
 __initcall(init_posix_cpu_timers);
index 0ac9053..2f76e06 100644 (file)
@@ -5092,17 +5092,16 @@ void account_idle_time(cputime_t cputime)
  */
 void account_process_tick(struct task_struct *p, int user_tick)
 {
-       cputime_t one_jiffy = jiffies_to_cputime(1);
-       cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
+       cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
        struct rq *rq = this_rq();
 
        if (user_tick)
-               account_user_time(p, one_jiffy, one_jiffy_scaled);
+               account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
        else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
-               account_system_time(p, HARDIRQ_OFFSET, one_jiffy,
+               account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,
                                    one_jiffy_scaled);
        else
-               account_idle_time(one_jiffy);
+               account_idle_time(cputime_one_jiffy);
 }
 
 /*
index 811e5c3..5db5a8d 100644 (file)
@@ -46,6 +46,9 @@
 #include <asm/timex.h>
 #include <asm/io.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/timer.h>
+
 u64 jiffies_64 __cacheline_aligned_in_smp = INITIAL_JIFFIES;
 
 EXPORT_SYMBOL(jiffies_64);
@@ -521,6 +524,25 @@ static inline void debug_timer_activate(struct timer_list *timer) { }
 static inline void debug_timer_deactivate(struct timer_list *timer) { }
 #endif
 
+static inline void debug_init(struct timer_list *timer)
+{
+       debug_timer_init(timer);
+       trace_timer_init(timer);
+}
+
+static inline void
+debug_activate(struct timer_list *timer, unsigned long expires)
+{
+       debug_timer_activate(timer);
+       trace_timer_start(timer, expires);
+}
+
+static inline void debug_deactivate(struct timer_list *timer)
+{
+       debug_timer_deactivate(timer);
+       trace_timer_cancel(timer);
+}
+
 static void __init_timer(struct timer_list *timer,
                         const char *name,
                         struct lock_class_key *key)
@@ -549,7 +571,7 @@ void init_timer_key(struct timer_list *timer,
                    const char *name,
                    struct lock_class_key *key)
 {
-       debug_timer_init(timer);
+       debug_init(timer);
        __init_timer(timer, name, key);
 }
 EXPORT_SYMBOL(init_timer_key);
@@ -568,7 +590,7 @@ static inline void detach_timer(struct timer_list *timer,
 {
        struct list_head *entry = &timer->entry;
 
-       debug_timer_deactivate(timer);
+       debug_deactivate(timer);
 
        __list_del(entry->prev, entry->next);
        if (clear_pending)
@@ -632,7 +654,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
                        goto out_unlock;
        }
 
-       debug_timer_activate(timer);
+       debug_activate(timer, expires);
 
        new_base = __get_cpu_var(tvec_bases);
 
@@ -787,7 +809,7 @@ void add_timer_on(struct timer_list *timer, int cpu)
        BUG_ON(timer_pending(timer) || !timer->function);
        spin_lock_irqsave(&base->lock, flags);
        timer_set_base(timer, base);
-       debug_timer_activate(timer);
+       debug_activate(timer, timer->expires);
        if (time_before(timer->expires, base->next_timer) &&
            !tbase_get_deferrable(timer->base))
                base->next_timer = timer->expires;
@@ -1000,7 +1022,9 @@ static inline void __run_timers(struct tvec_base *base)
                                 */
                                lock_map_acquire(&lockdep_map);
 
+                               trace_timer_expire_entry(timer);
                                fn(data);
+                               trace_timer_expire_exit(timer);
 
                                lock_map_release(&lockdep_map);