This accounts for CPU time spent polling for IO seperately from system
time.
Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
---
block/blk-core.c | 7 ++++++-
fs/proc/stat.c | 8 ++++++--
include/linux/kernel_stat.h | 1 +
include/linux/sched.h | 1 +
kernel/sched/cpuacct.c | 1 +
kernel/sched/cputime.c | 7 ++++++-
6 files changed, 21 insertions(+), 4 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 93810f2..b46fc2c 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -3330,6 +3330,7 @@ bool blk_poll(struct request_queue *q, blk_qc_t cookie)
if (plug)
blk_flush_plug_list(plug, false);
+ current->in_iopoll = 1;
state = current->state;
while (!need_resched()) {
unsigned int queue_num = blk_qc_t_to_queue_num(cookie);
@@ -3342,19 +3343,23 @@ bool blk_poll(struct request_queue *q, blk_qc_t cookie)
if (ret > 0) {
hctx->poll_success++;
set_current_state(TASK_RUNNING);
+ current->in_iopoll = 0;
return true;
}
if (signal_pending_state(state, current))
set_current_state(TASK_RUNNING);
- if (current->state == TASK_RUNNING)
+ if (current->state == TASK_RUNNING) {
+ current->in_iopoll = 0;
return true;
+ }
if (ret < 0)
break;
cpu_relax();
}
+ current->in_iopoll = 0;
return false;
}
diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 510413eb..5982efc 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -81,14 +81,14 @@ static int show_stat(struct seq_file *p, void *v)
{
int i, j;
unsigned long jif;
- u64 user, nice, system, idle, iowait, irq, softirq, steal;
+ u64 user, nice, system, idle, iowait, iopoll, irq, softirq, steal;
u64 guest, guest_nice;
u64 sum = 0;
u64 sum_softirq = 0;
unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
struct timespec boottime;
- user = nice = system = idle = iowait =
+ user = nice = system = idle = iowait = iopoll =
irq = softirq = steal = 0;
guest = guest_nice = 0;
getboottime(&boottime);
@@ -98,6 +98,7 @@ static int show_stat(struct seq_file *p, void *v)
user += kcpustat_cpu(i).cpustat[CPUTIME_USER];
nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE];
system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
+ iopoll += kcpustat_cpu(i).cpustat[CPUTIME_IOPOLL];
idle += get_idle_time(i);
iowait += get_iowait_time(i);
irq += kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
@@ -128,6 +129,7 @@ static int show_stat(struct seq_file *p, void *v)
seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(steal));
seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest));
seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest_nice));
+ seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(iopoll));
seq_putc(p, '\n');
for_each_online_cpu(i) {
@@ -135,6 +137,7 @@ static int show_stat(struct seq_file *p, void *v)
user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE];
system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
+ iopoll = kcpustat_cpu(i).cpustat[CPUTIME_IOPOLL];
idle = get_idle_time(i);
iowait = get_iowait_time(i);
irq = kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
@@ -153,6 +156,7 @@ static int show_stat(struct seq_file *p, void *v)
seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(steal));
seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest));
seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(guest_nice));
+ seq_put_decimal_ull(p, ' ', cputime64_to_clock_t(iopoll));
seq_putc(p, '\n');
}
seq_printf(p, "intr %llu", (unsigned long long)sum);
diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h
index 25a822f..c092745 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -28,6 +28,7 @@ enum cpu_usage_stat {
CPUTIME_STEAL,
CPUTIME_GUEST,
CPUTIME_GUEST_NICE,
+ CPUTIME_IOPOLL,
NR_STATS,
};
diff --git a/include/linux/sched.h b/include/linux/sched.h
index edad7a4..b34830e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1458,6 +1458,7 @@ struct task_struct {
unsigned in_execve:1; /* Tell the LSMs that the process is doing an
* execve */
unsigned in_iowait:1;
+ unsigned in_iopoll:1;
/* Revert to default priority/policy when forking */
unsigned sched_reset_on_fork:1;
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index dd7cbb5..5ad3ad4 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -200,6 +200,7 @@ static int cpuacct_stats_show(struct seq_file *sf, void *v)
for_each_online_cpu(cpu) {
struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
val += kcpustat->cpustat[CPUTIME_SYSTEM];
+ val += kcpustat->cpustat[CPUTIME_IOPOLL];
val += kcpustat->cpustat[CPUTIME_IRQ];
val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
}
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 05de80b..887c1a9 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -222,6 +222,8 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
index = CPUTIME_IRQ;
else if (in_serving_softirq())
index = CPUTIME_SOFTIRQ;
+ else if (p->in_iopoll)
+ index = CPUTIME_IOPOLL;
else
index = CPUTIME_SYSTEM;
@@ -367,7 +369,10 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
} else if (p->flags & PF_VCPU) { /* System time or guest time */
account_guest_time(p, cputime, scaled);
} else {
- __account_system_time(p, cputime, scaled, CPUTIME_SYSTEM);
+ if (p->in_iopoll)
+ __account_system_time(p, cputime, scaled, CPUTIME_IOPOLL);
+ else
+ __account_system_time(p, cputime, scaled, CPUTIME_SYSTEM);
}
}
--
2.6.2.307.g37023ba
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