[PATCH resend4 1/3] itimers: merge ITIMER_VIRT and ITIMER_PROFcommon code

From: Stanislaw Gruszka
Date: Fri May 22 2009 - 09:50:29 EST

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 <sgruszka@xxxxxxxxxx>
---
Compared to previous patch Thomas comments was applied (except one which goes
to 3/3 patch).

include/linux/posix-timers.h | 2 +
include/linux/sched.h | 14 +++-
kernel/fork.c | 8 +-
kernel/itimer.c | 146 +++++++++++++++++++----------------------
kernel/posix-cpu-timers.c | 98 +++++++++++++---------------
5 files changed, 131 insertions(+), 137 deletions(-)

diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 4f71bf4..71108e5 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -23,6 +23,8 @@ struct cpu_timer_list {
#define CPUCLOCK_PID_MASK 7
#define CPUCLOCK_PERTHREAD_MASK 4
#define CPUCLOCK_WHICH(clock) ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
+/* */
+
#define CPUCLOCK_CLOCK_MASK 3
#define CPUCLOCK_PROF 0
#define CPUCLOCK_VIRT 1
diff --git a/include/linux/sched.h b/include/linux/sched.h
index b4c38bc..a29aab8 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -454,6 +454,11 @@ 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
@@ -539,9 +544,12 @@ 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, mostly we
+ * use CPUCLOCK_PROF and CPUCLOCK_VIRT for indexing this 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 b9e2edd..fbde8e0 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -790,10 +790,10 @@ 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[0].expires = cputime_zero;
+ sig->it[0].incr = cputime_zero;
+ sig->it[1].expires = cputime_zero;
+ sig->it[1].incr = cputime_zero;

/* Cached expiration times. */
sig->cputime_expires.prof_exp = cputime_zero;
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, &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);
@@ -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 bece7c0..9b2d5e4 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(&current->sighand->siglock);
set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
spin_unlock_irq(&current->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;
--
1.5.5.6

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