From 42c4ab41a176ee784c0f28c0b29025a8fc34f05a Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 29 Jul 2009 12:15:26 +0200 Subject: 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 --- kernel/itimer.c | 146 ++++++++++++++++++++++++++------------------------------ 1 file changed, 68 insertions(+), 78 deletions(-) (limited to 'kernel/itimer.c') diff --git a/kernel/itimer.c b/kernel/itimer.c index 58762f7..852c88d 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; -- cgit v1.1 From 8356b5f9c424e5831715abbce747197c30d1fd71 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 29 Jul 2009 12:15:27 +0200 Subject: 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 --- kernel/itimer.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) (limited to 'kernel/itimer.c') diff --git a/kernel/itimer.c b/kernel/itimer.c index 852c88d..21adff7 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 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, - struct itimerval *value, struct itimerval *ovalue) + const struct itimerval *const value, + struct itimerval *const ovalue) { - cputime_t cval, cinterval, nval, ninterval; + 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); -- cgit v1.1 From a42548a18866e87092db93b771e6c5b060d78401 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Wed, 29 Jul 2009 12:15:29 +0200 Subject: 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 --- kernel/itimer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/itimer.c') diff --git a/kernel/itimer.c b/kernel/itimer.c index 21adff7..8078a32 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; -- cgit v1.1 From 3f0a525ebf4b8ef041a332bbe4a73aee94bb064b Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Mon, 10 Aug 2009 10:52:30 +0800 Subject: 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 --- kernel/itimer.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/itimer.c') diff --git a/kernel/itimer.c b/kernel/itimer.c index 8078a32..b03451e 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: -- cgit v1.1