[PATCH 07/15] print_integer, proc: rewrite /proc/stat via print_integer()
From: Alexey Dobriyan
Date: Mon Apr 20 2020 - 16:58:19 EST
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---
fs/proc/stat.c | 136 ++++++++++++++++++++++++++++++-------------------
1 file changed, 83 insertions(+), 53 deletions(-)
diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 678feb7b9949..859dc49cca85 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -14,6 +14,8 @@
#include <linux/sched/cputime.h>
#include <linux/tick.h>
+#include "../../lib/print-integer.h"
+
#ifndef arch_irq_stat_cpu
#define arch_irq_stat_cpu(cpu) 0
#endif
@@ -104,19 +106,30 @@ static void show_all_irqs(struct seq_file *p)
show_irq_gap(p, nr_irqs - next);
}
+enum {
+ USER,
+ NICE,
+ SYSTEM,
+ IDLE,
+ IOWAIT,
+ IRQ,
+ SOFTIRQ,
+ STEAL,
+ GUEST,
+ GUEST_NICE,
+
+ NR_VAL
+};
+
static int show_stat(struct seq_file *p, void *v)
{
+ u64 val[NR_VAL] = {};
int i, j;
- u64 user, nice, system, idle, iowait, irq, softirq, steal;
- u64 guest, guest_nice;
u64 sum = 0;
u64 sum_softirq = 0;
unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};
struct timespec64 boottime;
- user = nice = system = idle = iowait =
- irq = softirq = steal = 0;
- guest = guest_nice = 0;
getboottime64(&boottime);
for_each_possible_cpu(i) {
@@ -125,16 +138,16 @@ static int show_stat(struct seq_file *p, void *v)
kcpustat_cpu_fetch(&kcpustat, i);
- user += cpustat[CPUTIME_USER];
- nice += cpustat[CPUTIME_NICE];
- system += cpustat[CPUTIME_SYSTEM];
- idle += get_idle_time(&kcpustat, i);
- iowait += get_iowait_time(&kcpustat, i);
- irq += cpustat[CPUTIME_IRQ];
- softirq += cpustat[CPUTIME_SOFTIRQ];
- steal += cpustat[CPUTIME_STEAL];
- guest += cpustat[CPUTIME_GUEST];
- guest_nice += cpustat[CPUTIME_GUEST_NICE];
+ val[USER] += cpustat[CPUTIME_USER];
+ val[NICE] += cpustat[CPUTIME_NICE];
+ val[SYSTEM] += cpustat[CPUTIME_SYSTEM];
+ val[IDLE] += get_idle_time(&kcpustat, i);
+ val[IOWAIT] += get_iowait_time(&kcpustat, i);
+ val[IRQ] += cpustat[CPUTIME_IRQ];
+ val[SOFTIRQ] += cpustat[CPUTIME_SOFTIRQ];
+ val[STEAL] += cpustat[CPUTIME_STEAL];
+ val[GUEST] += cpustat[CPUTIME_GUEST];
+ val[GUEST_NICE] += cpustat[CPUTIME_GUEST_NICE];
sum += kstat_cpu_irqs_sum(i);
sum += arch_irq_stat_cpu(i);
@@ -147,47 +160,55 @@ static int show_stat(struct seq_file *p, void *v)
}
sum += arch_irq_stat();
- seq_put_decimal_ull(p, "cpu ", nsec_to_clock_t(user));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
- seq_putc(p, '\n');
+ {
+ char buf[4 + NR_VAL * (1 + 20) + 1];
+ char *q = buf + sizeof(buf);
+
+ *--q = '\n';
+ for (i = NR_VAL - 1; i >= 0; i--) {
+ q = _print_integer_u64(q, nsec_to_clock_t(val[i]));
+ *--q = ' ';
+ }
+ q = memcpy(q - 4, "cpu ", 4);
+
+ seq_write(p, q, buf + sizeof(buf) - q);
+ }
for_each_online_cpu(i) {
struct kernel_cpustat kcpustat;
u64 *cpustat = kcpustat.cpustat;
+ char buf[3 + 10 + NR_VAL * (1 + 20) + 1];
+ char *q = buf + sizeof(buf);
kcpustat_cpu_fetch(&kcpustat, i);
- /* Copy values here to work around gcc-2.95.3, gcc-2.96 */
- user = cpustat[CPUTIME_USER];
- nice = cpustat[CPUTIME_NICE];
- system = cpustat[CPUTIME_SYSTEM];
- idle = get_idle_time(&kcpustat, i);
- iowait = get_iowait_time(&kcpustat, i);
- irq = cpustat[CPUTIME_IRQ];
- softirq = cpustat[CPUTIME_SOFTIRQ];
- steal = cpustat[CPUTIME_STEAL];
- guest = cpustat[CPUTIME_GUEST];
- guest_nice = cpustat[CPUTIME_GUEST_NICE];
- seq_printf(p, "cpu%d", i);
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(user));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(system));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(idle));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(iowait));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(irq));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(softirq));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(steal));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest));
- seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice));
- seq_putc(p, '\n');
+ *--q = '\n';
+ q = _print_integer_u64(q, nsec_to_clock_t(cpustat[CPUTIME_GUEST_NICE]));
+ *--q = ' ';
+ q = _print_integer_u64(q, nsec_to_clock_t(cpustat[CPUTIME_GUEST]));
+ *--q = ' ';
+ q = _print_integer_u64(q, nsec_to_clock_t(cpustat[CPUTIME_STEAL]));
+ *--q = ' ';
+ q = _print_integer_u64(q, nsec_to_clock_t(cpustat[CPUTIME_SOFTIRQ]));
+ *--q = ' ';
+ q = _print_integer_u64(q, nsec_to_clock_t(cpustat[CPUTIME_IRQ]));
+ *--q = ' ';
+ q = _print_integer_u64(q, nsec_to_clock_t(cpustat[CPUTIME_IRQ]));
+ *--q = ' ';
+ q = _print_integer_u64(q, nsec_to_clock_t(get_iowait_time(&kcpustat, i)));
+ *--q = ' ';
+ q = _print_integer_u64(q, nsec_to_clock_t(get_idle_time(&kcpustat, i)));
+ *--q = ' ';
+ q = _print_integer_u64(q, nsec_to_clock_t(cpustat[CPUTIME_SYSTEM]));
+ *--q = ' ';
+ q = _print_integer_u64(q, nsec_to_clock_t(cpustat[CPUTIME_NICE]));
+ *--q = ' ';
+ q = _print_integer_u64(q, nsec_to_clock_t(cpustat[CPUTIME_USER]));
+ *--q = ' ';
+ q = _print_integer_u32(q, i);
+ q = memcpy(q - 3, "cpu", 3);
+
+ seq_write(p, q, buf + sizeof(buf) - q);
}
seq_put_decimal_ull(p, "intr ", (unsigned long long)sum);
@@ -205,11 +226,20 @@ static int show_stat(struct seq_file *p, void *v)
nr_running(),
nr_iowait());
- seq_put_decimal_ull(p, "softirq ", (unsigned long long)sum_softirq);
+ {
+ char buf[8 + 20 + (1 + 10) * NR_SOFTIRQS + 1];
+ char *q = buf + sizeof(buf);
- for (i = 0; i < NR_SOFTIRQS; i++)
- seq_put_decimal_ull(p, " ", per_softirq_sums[i]);
- seq_putc(p, '\n');
+ *--q = '\n';
+ for (i = NR_SOFTIRQS - 1; i >= 0; i--) {
+ q = _print_integer_u32(q, per_softirq_sums[i]);
+ *--q = ' ';
+ }
+ q = _print_integer_u64(q, sum_softirq);
+ q = memcpy(q - 8, "softirq ", 8);
+
+ seq_write(p, q, buf + sizeof(buf) - q);
+ }
return 0;
}
--
2.24.1