From 42c4ab41a176ee784c0f28c0b29025a8fc34f05a Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 29 Jul 2009 12:15:26 +0200 Subject: [PATCH 1/7] itimers: Merge ITIMER_VIRT and ITIMER_PROF Both cpu itimers have same data flow in the few places, this patch make unification of code related with VIRT and PROF itimers. Signed-off-by: Stanislaw Gruszka Acked-by: Peter Zijlstra Acked-by: Thomas Gleixner Cc: Oleg Nesterov Cc: Andrew Morton Cc: Paul Mackerras Cc: Benjamin Herrenschmidt LKML-Reference: <1248862529-6063-2-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 14 +++- kernel/fork.c | 9 +-- kernel/itimer.c | 146 ++++++++++++++++++-------------------- kernel/posix-cpu-timers.c | 98 ++++++++++++------------- 4 files changed, 130 insertions(+), 137 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 3ab08e4bb6b..3b3efaddd95 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -470,6 +470,11 @@ struct pacct_struct { unsigned long ac_minflt, ac_majflt; }; +struct cpu_itimer { + cputime_t expires; + cputime_t incr; +}; + /** * struct task_cputime - collected CPU time counts * @utime: time spent in user mode, in &cputime_t units @@ -564,9 +569,12 @@ 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/kernel/fork.c b/kernel/fork.c index 29b532e718f..893ab0bf5e3 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -62,6 +62,7 @@ #include #include #include +#include #include #include @@ -790,10 +791,10 @@ 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; diff --git a/kernel/itimer.c b/kernel/itimer.c index 58762f7077e..852c88ddd1f 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -41,10 +41,43 @@ 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 *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 = jiffies_to_cputime(1); + 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 +88,10 @@ 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, ×); - 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); @@ -128,6 +127,36 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer) return HRTIMER_NORESTART; } +static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, + struct itimerval *value, struct itimerval *ovalue) +{ + cputime_t cval, cinterval, nval, ninterval; + struct cpu_itimer *it = &tsk->signal->it[clock_id]; + + nval = timeval_to_cputime(&value->it_value); + ninterval = timeval_to_cputime(&value->it_interval); + + 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, jiffies_to_cputime(1)); + set_process_cpu_timer(tsk, clock_id, &nval, &cval); + } + it->expires = nval; + it->incr = ninterval; + + 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 +168,6 @@ 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. @@ -174,48 +202,10 @@ again: 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; diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index bece7c0b67b..9b2d5e4dc8c 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -14,11 +14,11 @@ */ 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(¤t->sighand->siglock); set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL); spin_unlock_irq(¤t->sighand->siglock); @@ -613,6 +613,9 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now) 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. */ @@ -620,30 +623,27 @@ 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, + if (!cputime_eq(sig->it[CPUCLOCK_VIRT].expires, cputime_zero) && - cputime_lt(p->signal->it_virt_expires, - timer->it.cpu.expires.cpu)) + cputime_lt(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, + if (!cputime_eq(sig->it[CPUCLOCK_PROF].expires, cputime_zero) && - cputime_lt(p->signal->it_prof_expires, - timer->it.cpu.expires.cpu)) + cputime_lt(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; } } @@ -1070,6 +1070,27 @@ static void stop_process_timers(struct task_struct *tsk) spin_unlock_irqrestore(&cputimer->lock, flags); } +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)) { + it->expires = it->incr; + if (!cputime_eq(it->expires, cputime_zero)) + it->expires = cputime_add(it->expires, 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 @@ -1089,10 +1110,10 @@ 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; @@ -1152,38 +1173,11 @@ 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; From 8356b5f9c424e5831715abbce747197c30d1fd71 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 29 Jul 2009 12:15:27 +0200 Subject: [PATCH 2/7] itimers: Fix periodic tics precision Measure ITIMER_PROF and ITIMER_VIRT timers interval error between real ticks and requested by user. Take it into account when scheduling next tick. This patch introduce possibility where time between two consecutive tics is smaller then requested interval, it preserve however dependency that n tick is generated not earlier than n*interval time - counting from the beginning of periodic signal generation. Signed-off-by: Stanislaw Gruszka Acked-by: Peter Zijlstra Acked-by: Thomas Gleixner Cc: Oleg Nesterov Cc: Andrew Morton Cc: Paul Mackerras Cc: Benjamin Herrenschmidt LKML-Reference: <1248862529-6063-3-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 2 ++ kernel/itimer.c | 26 ++++++++++++++++++++++---- kernel/posix-cpu-timers.c | 20 +++++++++++++++++--- 3 files changed, 41 insertions(+), 7 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 3b3efaddd95..a069e65e8bb 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -473,6 +473,8 @@ struct pacct_struct { struct cpu_itimer { cputime_t expires; cputime_t incr; + u32 error; + u32 incr_error; }; /** diff --git a/kernel/itimer.c b/kernel/itimer.c index 852c88ddd1f..21adff7b2a1 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -42,7 +42,7 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer) } static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, - struct itimerval *value) + struct itimerval *const value) { cputime_t cval, cinterval; struct cpu_itimer *it = &tsk->signal->it[clock_id]; @@ -127,14 +127,32 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer) return HRTIMER_NORESTART; } -static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, - struct itimerval *value, struct itimerval *ovalue) +static inline u32 cputime_sub_ns(cputime_t ct, s64 real_ns) { - cputime_t cval, cinterval, nval, ninterval; + 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); diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 9b2d5e4dc8c..b60d644ea4b 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1070,6 +1070,8 @@ 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) { @@ -1077,9 +1079,16 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, return; if (cputime_ge(cur_time, it->expires)) { - it->expires = it->incr; - if (!cputime_eq(it->expires, cputime_zero)) - it->expires = cputime_add(it->expires, cur_time); + 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, + jiffies_to_cputime(1)); + it->error -= onecputick; + } + } else + it->expires = cputime_zero; __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); } @@ -1696,10 +1705,15 @@ 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(jiffies_to_cputime(1), &ts); + onecputick = ts.tv_nsec; + WARN_ON(ts.tv_sec != 0); + return 0; } __initcall(init_posix_cpu_timers); From d1e3b6d195770bd422e3229b88edfc154b6a27dd Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 29 Jul 2009 12:15:28 +0200 Subject: [PATCH 3/7] itimers: Simplify arm_timer() code a bit Don't update values in expiration cache when new ones are equal. Add expire_le() and expire_gt() helpers to simplify the code. Signed-off-by: Stanislaw Gruszka Acked-by: Peter Zijlstra Acked-by: Thomas Gleixner Cc: Oleg Nesterov Cc: Andrew Morton Cc: Paul Mackerras Cc: Benjamin Herrenschmidt LKML-Reference: <1248862529-6063-4-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar --- kernel/posix-cpu-timers.c | 44 ++++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 21 deletions(-) diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index b60d644ea4b..69c92374355 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -541,6 +541,17 @@ 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 @@ -585,31 +596,26 @@ 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 { @@ -623,17 +629,13 @@ static void arm_timer(struct k_itimer *timer, union cpu_time_count now) default: BUG(); case CPUCLOCK_VIRT: - if (!cputime_eq(sig->it[CPUCLOCK_VIRT].expires, - cputime_zero) && - cputime_lt(sig->it[CPUCLOCK_VIRT].expires, + if (expires_le(sig->it[CPUCLOCK_VIRT].expires, exp->cpu)) break; sig->cputime_expires.virt_exp = exp->cpu; break; case CPUCLOCK_PROF: - if (!cputime_eq(sig->it[CPUCLOCK_PROF].expires, - cputime_zero) && - cputime_lt(sig->it[CPUCLOCK_PROF].expires, + if (expires_le(sig->it[CPUCLOCK_PROF].expires, exp->cpu)) break; i = sig->rlim[RLIMIT_CPU].rlim_cur; From a42548a18866e87092db93b771e6c5b060d78401 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 29 Jul 2009 12:15:29 +0200 Subject: [PATCH 4/7] cputime: Optimize jiffies_to_cputime(1) For powerpc with CONFIG_VIRT_CPU_ACCOUNTING jiffies_to_cputime(1) is not compile time constant and run time calculations are quite expensive. To optimize we use precomputed value. For all other architectures is is preprocessor definition. Signed-off-by: Stanislaw Gruszka Acked-by: Peter Zijlstra Acked-by: Thomas Gleixner Cc: Oleg Nesterov Cc: Andrew Morton Cc: Paul Mackerras Cc: Benjamin Herrenschmidt LKML-Reference: <1248862529-6063-5-git-send-email-sgruszka@redhat.com> Signed-off-by: Ingo Molnar --- arch/ia64/include/asm/cputime.h | 1 + arch/powerpc/include/asm/cputime.h | 13 +++++++++++++ arch/powerpc/kernel/time.c | 4 ++++ arch/s390/include/asm/cputime.h | 1 + include/asm-generic/cputime.h | 1 + kernel/itimer.c | 4 ++-- kernel/posix-cpu-timers.c | 6 +++--- kernel/sched.c | 9 ++++----- 8 files changed, 29 insertions(+), 10 deletions(-) diff --git a/arch/ia64/include/asm/cputime.h b/arch/ia64/include/asm/cputime.h index d20b998cb91..7fa8a859466 100644 --- a/arch/ia64/include/asm/cputime.h +++ b/arch/ia64/include/asm/cputime.h @@ -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)) diff --git a/arch/powerpc/include/asm/cputime.h b/arch/powerpc/include/asm/cputime.h index f42e623030e..fa19f3fe05f 100644 --- a/arch/powerpc/include/asm/cputime.h +++ b/arch/powerpc/include/asm/cputime.h @@ -18,6 +18,9 @@ #ifndef CONFIG_VIRT_CPU_ACCOUNTING #include +#ifdef __KERNEL__ +static inline void setup_cputime_one_jiffy(void) { } +#endif #else #include @@ -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; diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index eae4511ceea..211d7b0cd37 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -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; @@ -500,6 +502,7 @@ 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" @@ -945,6 +948,7 @@ 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 diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h index 7a3817a656d..24b1244aadb 100644 --- a/arch/s390/include/asm/cputime.h +++ b/arch/s390/include/asm/cputime.h @@ -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)) diff --git a/include/asm-generic/cputime.h b/include/asm-generic/cputime.h index 1c1fa422d18..ca0f239f0e1 100644 --- a/include/asm-generic/cputime.h +++ b/include/asm-generic/cputime.h @@ -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)) diff --git a/kernel/itimer.c b/kernel/itimer.c index 21adff7b2a1..8078a32d3b1 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -64,7 +64,7 @@ static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, if (cputime_le(cval, t)) /* about to fire */ - cval = jiffies_to_cputime(1); + cval = cputime_one_jiffy; else cval = cputime_sub(cval, t); } @@ -161,7 +161,7 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, 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)); + nval = cputime_add(nval, cputime_one_jiffy); set_process_cpu_timer(tsk, clock_id, &nval, &cval); } it->expires = nval; diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 69c92374355..18bdde6f676 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -1086,7 +1086,7 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, it->error += it->incr_error; if (it->error >= onecputick) { it->expires = cputime_sub(it->expires, - jiffies_to_cputime(1)); + cputime_one_jiffy); it->error -= onecputick; } } else @@ -1461,7 +1461,7 @@ 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); } @@ -1712,7 +1712,7 @@ static __init int init_posix_cpu_timers(void) register_posix_clock(CLOCK_PROCESS_CPUTIME_ID, &process); register_posix_clock(CLOCK_THREAD_CPUTIME_ID, &thread); - cputime_to_timespec(jiffies_to_cputime(1), &ts); + cputime_to_timespec(cputime_one_jiffy, &ts); onecputick = ts.tv_nsec; WARN_ON(ts.tv_sec != 0); diff --git a/kernel/sched.c b/kernel/sched.c index 1b59e265273..8f977d5cc51 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -5031,17 +5031,16 @@ 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); } /* From 2b022e3d4bf9885f781221c59d86283a2cdfc2ed Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 10 Aug 2009 10:48:59 +0800 Subject: [PATCH 5/7] timers: Add tracepoints for timer_list timers Add tracepoints which cover the timer life cycle. The tracepoints are integrated with the already existing debug_object debug points as far as possible. Based on patches from Mathieu: http://marc.info/?l=linux-kernel&m=123791201816247&w=2 and Anton: http://marc.info/?l=linux-kernel&m=124331396919301&w=2 [ tglx: Fixed timeout value in timer_start tracepoint, massaged comments and made the printk's more readable ] Signed-off-by: Xiao Guangrong Cc: Anton Blanchard Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Mathieu Desnoyers Cc: Peter Zijlstra Cc: KOSAKI Motohiro Cc: Zhaolei LKML-Reference: <4A7F8A9B.3040201@cn.fujitsu.com> Signed-off-by: Thomas Gleixner --- include/trace/events/timer.h | 137 +++++++++++++++++++++++++++++++++++ kernel/timer.c | 32 +++++++- 2 files changed, 165 insertions(+), 4 deletions(-) create mode 100644 include/trace/events/timer.h diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h new file mode 100644 index 00000000000..725892a93b4 --- /dev/null +++ b/include/trace/events/timer.h @@ -0,0 +1,137 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM timer + +#if !defined(_TRACE_TIMER_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_TIMER_H + +#include +#include + +/** + * 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) +); + +#endif /* _TRACE_TIMER_H */ + +/* This part must be outside protection */ +#include diff --git a/kernel/timer.c b/kernel/timer.c index 8e92be654da..a7352b00703 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -46,6 +46,9 @@ #include #include +#define CREATE_TRACE_POINTS +#include + 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); From c6a2a1770245f654f35f60e1458d4356680f9519 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 10 Aug 2009 10:51:23 +0800 Subject: [PATCH 6/7] hrtimer: Add tracepoint for hrtimers Add tracepoints which cover the life cycle of a hrtimer. The tracepoints are integrated with the already existing debug_object debug points as far as possible. [ tglx: Fixed comments, made output conistent, easier to read and parse. Fixed output for 32bit archs which do not use the scalar representation of ktime_t. Hand current time to trace_hrtimer_expiry_entry instead of calling get_time() inside of the trace assignment. ] Signed-off-by: Xiao Guangrong Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Mathieu Desnoyers Cc: Anton Blanchard Cc: Peter Zijlstra Cc: KOSAKI Motohiro Cc: Zhaolei LKML-Reference: <4A7F8B2B.5020908@cn.fujitsu.com> Signed-off-by: Thomas Gleixner --- include/trace/events/timer.h | 139 +++++++++++++++++++++++++++++++++++ kernel/hrtimer.c | 40 ++++++++-- 2 files changed, 171 insertions(+), 8 deletions(-) diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h index 725892a93b4..df3c07fa0cb 100644 --- a/include/trace/events/timer.h +++ b/include/trace/events/timer.h @@ -5,6 +5,7 @@ #define _TRACE_TIMER_H #include +#include #include /** @@ -131,6 +132,144 @@ TRACE_EVENT(timer_cancel, 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) +); + #endif /* _TRACE_TIMER_H */ /* This part must be outside protection */ diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index e2f91ecc01a..b44d1b07377 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -48,6 +48,8 @@ #include +#include + /* * The timer bases: * @@ -441,6 +443,26 @@ 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 @@ -797,7 +819,7 @@ 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: @@ -883,7 +905,7 @@ 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, @@ -1116,7 +1138,7 @@ 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); @@ -1140,7 +1162,7 @@ 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; @@ -1149,7 +1171,7 @@ 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; @@ -1160,7 +1182,9 @@ 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); /* @@ -1271,7 +1295,7 @@ void hrtimer_interrupt(struct clock_event_device *dev) break; } - __run_hrtimer(timer); + __run_hrtimer(timer, &basenow); } base++; } @@ -1393,7 +1417,7 @@ 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); } @@ -1569,7 +1593,7 @@ 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 From 3f0a525ebf4b8ef041a332bbe4a73aee94bb064b Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 10 Aug 2009 10:52:30 +0800 Subject: [PATCH 7/7] itimers: Add tracepoints for itimer Add tracepoints for all itimer variants: ITIMER_REAL, ITIMER_VIRTUAL and ITIMER_PROF. [ tglx: Fixed comments and made the output more readable, parseable and consistent. Replaced pid_vnr by pid_nr because the hrtimer callback can happen in any namespace ] Signed-off-by: Xiao Guangrong Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Mathieu Desnoyers Cc: Anton Blanchard Cc: Peter Zijlstra Cc: KOSAKI Motohiro Cc: Zhaolei LKML-Reference: <4A7F8B6E.2010109@cn.fujitsu.com> Signed-off-by: Thomas Gleixner --- include/trace/events/timer.h | 66 ++++++++++++++++++++++++++++++++++++ kernel/itimer.c | 5 +++ kernel/posix-cpu-timers.c | 7 +++- 3 files changed, 77 insertions(+), 1 deletion(-) diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h index df3c07fa0cb..1844c48d640 100644 --- a/include/trace/events/timer.h +++ b/include/trace/events/timer.h @@ -270,6 +270,72 @@ TRACE_EVENT(hrtimer_cancel, 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 */ diff --git a/kernel/itimer.c b/kernel/itimer.c index 8078a32d3b1..b03451ede52 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -12,6 +12,7 @@ #include #include #include +#include #include @@ -122,6 +123,7 @@ 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; @@ -166,6 +168,8 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id, } 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); @@ -217,6 +221,7 @@ 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: diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c index 12161f74744..5c9dc228747 100644 --- a/kernel/posix-cpu-timers.c +++ b/kernel/posix-cpu-timers.c @@ -8,6 +8,7 @@ #include #include #include +#include /* * Called after updating RLIMIT_CPU to set timer expiration if necessary. @@ -1090,9 +1091,13 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, cputime_one_jiffy); it->error -= onecputick; } - } else + } 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); }