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itimers: Merge ITIMER_VIRT and ITIMER_PROF
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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@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
LKML-Reference: <1248862529-6063-2-git-send-email-sgruszka@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Stanislaw Gruszka authored and Ingo Molnar committed Aug 3, 2009
1 parent ed680c4 commit 42c4ab4
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Showing 4 changed files with 130 additions and 137 deletions.
14 changes: 11 additions & 3 deletions include/linux/sched.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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.
Expand Down
9 changes: 5 additions & 4 deletions kernel/fork.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,7 @@
#include <linux/fs_struct.h>
#include <linux/magic.h>
#include <linux/perf_counter.h>
#include <linux/posix-timers.h>

#include <asm/pgtable.h>
#include <asm/pgalloc.h>
Expand Down Expand Up @@ -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;
Expand Down
146 changes: 68 additions & 78 deletions kernel/itimer.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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:
Expand All @@ -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);
Expand Down Expand Up @@ -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
*/
Expand All @@ -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.
Expand Down Expand Up @@ -174,48 +202,10 @@ int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
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;
Expand Down
98 changes: 46 additions & 52 deletions kernel/posix-cpu-timers.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -613,37 +613,37 @@ 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.
*/
switch (CPUCLOCK_WHICH(timer->it_clock)) {
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;
}
}
Expand Down Expand Up @@ -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
Expand All @@ -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;
Expand Down Expand Up @@ -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;
Expand Down

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