[RFC PATCH] posix-cpu-timers: optimize callingthread_group_cputime()

From: Stanislaw Gruszka
Date: Fri Jun 12 2009 - 06:46:00 EST

When we call thread_group_cputime() we not always need all 3 cputime values.
Use additional mask to specify which fields of struct task_cputime is caller
interested. Similarly cputimer is changed to make cputimer->running mask
of currently accounted cpu times.

Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
---
fs/binfmt_elf.c | 3 +-
fs/binfmt_elf_fdpic.c | 2 +-
fs/proc/array.c | 4 ++-
include/linux/sched.h | 12 +++++++++-
kernel/exit.c | 3 +-
kernel/fork.c | 2 +-
kernel/itimer.c | 6 +++-
kernel/posix-cpu-timers.c | 48 +++++++++++++++++++++++++++++---------------
kernel/sched.c | 2 +-
kernel/sched_stats.h | 6 ++--
kernel/sys.c | 7 ++++-
11 files changed, 63 insertions(+), 32 deletions(-)

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 40381df..d5f4efd 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1351,7 +1351,8 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
* This is the record for the group leader. It shows the
* group-wide total, not its individual thread total.
*/
- thread_group_cputime(p, &cputime);
+ thread_group_cputime(p, &cputime,
+ TG_CPUCLOCK_UTIME | TG_CPUCLOCK_STIME);
cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
} else {
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index fdb66fa..004a141 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -1398,7 +1398,7 @@ static void fill_prstatus(struct elf_prstatus *prstatus,
* This is the record for the group leader. It shows the
* group-wide total, not its individual thread total.
*/
- thread_group_cputime(p, &cputime);
+ thread_group_cputime(p, &cputime, TG_UTIME | TG_STIME);
cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
} else {
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 725a650..c517495 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -416,7 +416,9 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,

min_flt += sig->min_flt;
maj_flt += sig->maj_flt;
- thread_group_cputime(task, &cputime);
+ thread_group_cputime(task, &cputime,
+ TG_CPUCLOCK_UTIME |
+ TG_CPUCLOCK_STIME);
utime = cputime.utime;
stime = cputime.stime;
gtime = cputime_add(gtime, sig->gtime);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index d139966..872974a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2267,8 +2267,16 @@ static inline int spin_needbreak(spinlock_t *lock)
/*
* Thread group CPU time accounting.
*/
-void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times);
-void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times);
+
+#define TG_CPUCLOCK_UTIME 0x1
+#define TG_CPUCLOCK_STIME 0x2
+#define TG_CPUCLOCK_SCHED 0x4
+#define TG_CPUCLOCK_ALL 0x7
+
+void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times,
+ int mask);
+void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times,
+ int mask);

static inline void thread_group_cputime_init(struct signal_struct *sig)
{
diff --git a/kernel/exit.c b/kernel/exit.c
index cab535c..155c4cd 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1205,7 +1205,8 @@ static int wait_task_zombie(struct task_struct *p, int options,
* group, which consolidates times for all threads in the
* group including the group leader.
*/
- thread_group_cputime(p, &cputime);
+ thread_group_cputime(p, &cputime,
+ TG_CPUCLOCK_UTIME | TG_CPUCLOCK_STIME);
spin_lock_irq(&p->parent->sighand->siglock);
psig = p->parent->signal;
sig = p->signal;
diff --git a/kernel/fork.c b/kernel/fork.c
index bb762b4..4229223 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -802,7 +802,7 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig)
if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
sig->cputime_expires.prof_exp =
secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
- sig->cputimer.running = 1;
+ sig->cputimer.running = TG_CPUCLOCK_SCHED;
}

/* The timer lists. */
diff --git a/kernel/itimer.c b/kernel/itimer.c
index 58762f7..0e29bd6 100644
--- a/kernel/itimer.c
+++ b/kernel/itimer.c
@@ -62,7 +62,7 @@ int do_getitimer(int which, struct itimerval *value)
struct task_cputime cputime;
cputime_t utime;

- thread_group_cputimer(tsk, &cputime);
+ thread_group_cputimer(tsk, &cputime, TG_CPUCLOCK_UTIME);
utime = cputime.utime;
if (cputime_le(cval, utime)) { /* about to fire */
cval = jiffies_to_cputime(1);
@@ -82,7 +82,9 @@ int do_getitimer(int which, struct itimerval *value)
struct task_cputime times;
cputime_t ptime;

- thread_group_cputimer(tsk, &times);
+ thread_group_cputimer(tsk, &times,
+ TG_CPUCLOCK_UTIME |
+ TG_CPUCLOCK_STIME);
ptime = cputime_add(times.utime, times.stime);
if (cputime_le(cval, ptime)) { /* about to fire */
cval = jiffies_to_cputime(1);
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 1d9cdf3..b5f1b44 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -230,7 +230,8 @@ static int cpu_clock_sample(const clockid_t which_clock, struct task_struct *p,
return 0;
}

-void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)
+void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times,
+ int mask)
{
struct sighand_struct *sighand;
struct signal_struct *sig;
@@ -247,16 +248,22 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times)

t = tsk;
do {
- times->utime = cputime_add(times->utime, t->utime);
- times->stime = cputime_add(times->stime, t->stime);
- times->sum_exec_runtime += t->se.sum_exec_runtime;
+ if (mask & TG_CPUCLOCK_UTIME)
+ times->utime = cputime_add(times->utime, t->utime);
+ if (mask & TG_CPUCLOCK_STIME)
+ times->stime = cputime_add(times->stime, t->stime);
+ if (mask & TG_CPUCLOCK_SCHED)
+ times->sum_exec_runtime += t->se.sum_exec_runtime;

t = next_thread(t);
} while (t != tsk);

- times->utime = cputime_add(times->utime, sig->utime);
- times->stime = cputime_add(times->stime, sig->stime);
- times->sum_exec_runtime += sig->sum_sched_runtime;
+ if (mask & TG_CPUCLOCK_UTIME)
+ times->utime = cputime_add(times->utime, sig->utime);
+ if (mask & TG_CPUCLOCK_STIME)
+ times->stime = cputime_add(times->stime, sig->stime);
+ if (mask & TG_CPUCLOCK_SCHED)
+ times->sum_exec_runtime += sig->sum_sched_runtime;
out:
rcu_read_unlock();
}
@@ -273,22 +280,25 @@ static void update_gt_cputime(struct task_cputime *a, struct task_cputime *b)
a->sum_exec_runtime = b->sum_exec_runtime;
}

-void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times)
+void thread_group_cputimer(struct task_struct *tsk, struct task_cputime *times,
+ int mask)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
struct task_cputime sum;
unsigned long flags;
+ int new_clocks;

spin_lock_irqsave(&cputimer->lock, flags);
- if (!cputimer->running) {
- cputimer->running = 1;
+ if ((cputimer->running & mask) != mask) {
+ new_clocks = (cputimer->running ^ mask) & mask;
+ cputimer->running |= mask;
/*
* The POSIX timer interface allows for absolute time expiry
* values through the TIMER_ABSTIME flag, therefore we have
* to synchronize the timer to the clock every time we start
* it.
*/
- thread_group_cputime(tsk, &sum);
+ thread_group_cputime(tsk, &sum, new_clocks);
update_gt_cputime(&cputimer->cputime, &sum);
}
*times = cputimer->cputime;
@@ -309,11 +319,12 @@ static int cpu_clock_sample_group(const clockid_t which_clock,
default:
return -EINVAL;
case CPUCLOCK_PROF:
- thread_group_cputime(p, &cputime);
+ thread_group_cputime(p, &cputime,
+ TG_CPUCLOCK_STIME | TG_CPUCLOCK_UTIME);
cpu->cpu = cputime_add(cputime.utime, cputime.stime);
break;
case CPUCLOCK_VIRT:
- thread_group_cputime(p, &cputime);
+ thread_group_cputime(p, &cputime, TG_CPUCLOCK_UTIME);
cpu->cpu = cputime.utime;
break;
case CPUCLOCK_SCHED:
@@ -523,7 +534,7 @@ void posix_cpu_timers_exit_group(struct task_struct *tsk)
{
struct task_cputime cputime;

- thread_group_cputimer(tsk, &cputime);
+ thread_group_cputimer(tsk, &cputime, TG_CPUCLOCK_ALL);
cleanup_timers(tsk->signal->cpu_timers,
cputime.utime, cputime.stime, cputime.sum_exec_runtime);
}
@@ -691,17 +702,20 @@ static int cpu_timer_sample_group(const clockid_t which_clock,
{
struct task_cputime cputime;

- thread_group_cputimer(p, &cputime);
switch (CPUCLOCK_WHICH(which_clock)) {
default:
return -EINVAL;
case CPUCLOCK_PROF:
+ thread_group_cputimer(p, &cputime,
+ TG_CPUCLOCK_UTIME | TG_CPUCLOCK_STIME);
cpu->cpu = cputime_add(cputime.utime, cputime.stime);
break;
case CPUCLOCK_VIRT:
+ thread_group_cputimer(p, &cputime, TG_CPUCLOCK_UTIME);
cpu->cpu = cputime.utime;
break;
case CPUCLOCK_SCHED:
+ thread_group_cputimer(p, &cputime, TG_CPUCLOCK_SCHED);
cpu->sched = cputime.sum_exec_runtime + task_delta_exec(p);
break;
}
@@ -1101,7 +1115,7 @@ static void check_process_timers(struct task_struct *tsk,
/*
* Collect the current process totals.
*/
- thread_group_cputimer(tsk, &cputime);
+ thread_group_cputimer(tsk, &cputime, TG_CPUCLOCK_ALL);
utime = cputime.utime;
ptime = cputime_add(utime, cputime.stime);
sum_sched_runtime = cputime.sum_exec_runtime;
@@ -1367,7 +1381,7 @@ static inline int fastpath_timer_check(struct task_struct *tsk)
if (!task_cputime_zero(&sig->cputime_expires)) {
struct task_cputime group_sample;

- thread_group_cputimer(tsk, &group_sample);
+ thread_group_cputimer(tsk, &group_sample, TG_CPUCLOCK_ALL);
if (task_cputime_expired(&group_sample, &sig->cputime_expires))
return 1;
}
diff --git a/kernel/sched.c b/kernel/sched.c
index 14c447a..fe6e0ac 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4828,7 +4828,7 @@ unsigned long long thread_group_sched_runtime(struct task_struct *p)
u64 ns;

rq = task_rq_lock(p, &flags);
- thread_group_cputime(p, &totals);
+ thread_group_cputime(p, &totals, TG_CPUCLOCK_SCHED);
ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq);
task_rq_unlock(rq, &flags);

diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 32d2bd4..9156e44 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -303,7 +303,7 @@ static inline void account_group_user_time(struct task_struct *tsk,

cputimer = &tsk->signal->cputimer;

- if (!cputimer->running)
+ if (!(cputimer->running & TG_CPUCLOCK_UTIME))
return;

spin_lock(&cputimer->lock);
@@ -333,7 +333,7 @@ static inline void account_group_system_time(struct task_struct *tsk,

cputimer = &tsk->signal->cputimer;

- if (!cputimer->running)
+ if (!(cputimer->running & TG_CPUCLOCK_STIME))
return;

spin_lock(&cputimer->lock);
@@ -366,7 +366,7 @@ static inline void account_group_exec_runtime(struct task_struct *tsk,

cputimer = &sig->cputimer;

- if (!cputimer->running)
+ if (!(cputimer->running & TG_CPUCLOCK_SCHED))
return;

spin_lock(&cputimer->lock);
diff --git a/kernel/sys.c b/kernel/sys.c
index 0805d08..69d64f0 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -914,7 +914,8 @@ void do_sys_times(struct tms *tms)
cputime_t cutime, cstime;

spin_lock_irq(&current->sighand->siglock);
- thread_group_cputime(current, &cputime);
+ thread_group_cputime(current, &cputime,
+ TG_CPUCLOCK_UTIME | TG_CPUCLOCK_STIME);
cutime = current->signal->cutime;
cstime = current->signal->cstime;
spin_unlock_irq(&current->sighand->siglock);
@@ -1650,7 +1651,9 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
break;

case RUSAGE_SELF:
- thread_group_cputime(p, &cputime);
+ thread_group_cputime(p, &cputime,
+ TG_CPUCLOCK_UTIME |
+ TG_CPUCLOCK_STIME);
utime = cputime_add(utime, cputime.utime);
stime = cputime_add(stime, cputime.stime);
r->ru_nvcsw += p->signal->nvcsw;
--
1.6.0.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/