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| author | Arjan van de Ven <arjan@linux.intel.com> | 2009-07-20 11:26:58 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-09-02 08:44:08 +0200 |
| commit | 8f0dfc34e9b323a028c2ec41abb7e9de477b7a94 (patch) | |
| tree | fa7e44d9ad3eb22517f0724e71f9812f71a16ae2 /kernel | |
| parent | f14eff1cc2f418a7c5e23aedc6a1bdca3343b871 (diff) | |
| download | kernel_samsung_smdk4412-8f0dfc34e9b323a028c2ec41abb7e9de477b7a94.zip kernel_samsung_smdk4412-8f0dfc34e9b323a028c2ec41abb7e9de477b7a94.tar.gz kernel_samsung_smdk4412-8f0dfc34e9b323a028c2ec41abb7e9de477b7a94.tar.bz2 | |
sched: Provide iowait counters
For counting how long an application has been waiting for
(disk) IO, there currently is only the HZ sample driven
information available, while for all other counters in this
class, a high resolution version is available via
CONFIG_SCHEDSTATS.
In order to make an improved bootchart tool possible, we also
need a higher resolution version of the iowait time.
This patch below adds this scheduler statistic to the kernel.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4A64B813.1080506@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 4 | ||||
| -rw-r--r-- | kernel/sched_debug.c | 4 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 5 |
3 files changed, 13 insertions, 0 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 6244d24..38d05a8 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6754,7 +6754,9 @@ void __sched io_schedule(void) delayacct_blkio_start(); atomic_inc(&rq->nr_iowait); + current->in_iowait = 1; schedule(); + current->in_iowait = 0; atomic_dec(&rq->nr_iowait); delayacct_blkio_end(); } @@ -6767,7 +6769,9 @@ long __sched io_schedule_timeout(long timeout) delayacct_blkio_start(); atomic_inc(&rq->nr_iowait); + current->in_iowait = 1; ret = schedule_timeout(timeout); + current->in_iowait = 0; atomic_dec(&rq->nr_iowait); delayacct_blkio_end(); return ret; diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index 70c7e0b..5ddbd08 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -409,6 +409,8 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) PN(se.wait_max); PN(se.wait_sum); P(se.wait_count); + PN(se.iowait_sum); + P(se.iowait_count); P(sched_info.bkl_count); P(se.nr_migrations); P(se.nr_migrations_cold); @@ -479,6 +481,8 @@ void proc_sched_set_task(struct task_struct *p) p->se.wait_max = 0; p->se.wait_sum = 0; p->se.wait_count = 0; + p->se.iowait_sum = 0; + p->se.iowait_count = 0; p->se.sleep_max = 0; p->se.sum_sleep_runtime = 0; p->se.block_max = 0; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 342000b..471fa28 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -652,6 +652,11 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) se->sum_sleep_runtime += delta; if (tsk) { + if (tsk->in_iowait) { + se->iowait_sum += delta; + se->iowait_count++; + } + /* * Blocking time is in units of nanosecs, so shift by * 20 to get a milliseconds-range estimation of the |