[PATCH 2/3 v2] proc: Export statistics for softirq to /proc

Keika Kobayashi
2008-11-22T04:27:20Z

Export statistics for softirq in /proc/softirqs and /proc/stat.

1. /proc/softirqs
Implement /proc/softirqs which shows the number of softirq
for each CPU like /proc/interrupts.

2. /proc/stat
Add the "softirq" line to /proc/stat.
This line shows the number of softirq for all cpu.
The first column is the total of all softirqs and
each subsequent column is the total for particular softirq.

Signed-off-by: Keika Kobayashi <kobayashi.kk@ncos.nec.co.jp>
Reviewed-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
---
fs/proc/Makefile | 1 +
fs/proc/softirqs.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/proc/stat.c | 17 +++++++++++++++
3 files changed, 75 insertions(+), 0 deletions(-)
create mode 100644 fs/proc/softirqs.c

diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index 63d9651..11a7b5c 100644
--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -18,6 +18,7 @@ proc-y += meminfo.o
proc-y += stat.o
proc-y += uptime.o
proc-y += version.o
+proc-y += softirqs.o
proc-$(CONFIG_PROC_SYSCTL) += proc_sysctl.o
proc-$(CONFIG_NET) += proc_net.o
proc-$(CONFIG_PROC_KCORE) += kcore.o
diff --git a/fs/proc/softirqs.c b/fs/proc/softirqs.c
new file mode 100644
index 0000000..543f9d9
--- /dev/null
+++ b/fs/proc/softirqs.c
@@ -0,0 +1,57 @@
+#include <linux/init.h>
+#include <linux/kernel_stat.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+static const char *desc_array[] = {
+ "HI",
+ "TIMER",
+ "NET_TX",
+ "NET_RX",
+ "BLOCK",
+ "TASKLET",
+ "SCHED",
+#ifdef CONFIG_HIGH_RES_TIMERS
+ "HRTIMER",
+#endif
+ "RCU"};
+
+/*
+ * /proc/softirqs ... display the number of softirqs
+ */
+static int show_softirqs(struct seq_file *p, void *v)
+{
+ int i, j;
+
+ seq_printf(p, " ");
+ for_each_possible_cpu(i)
+ seq_printf(p, "CPU%-8d", i);
+ seq_printf(p, "\n");
+
+ for (i = 0; i < NR_SOFTIRQS; i++) {
+ seq_printf(p, "%-9s", desc_array[i]);
+ for_each_possible_cpu(j)
+ seq_printf(p, " %10u", kstat_softirqs_cpu(i, j));
+ seq_printf(p, "\n");
+ }
+ return 0;
+}
+
+static int softirqs_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, show_softirqs, NULL);
+}
+
+static const struct file_operations proc_softirqs_operations = {
+ .open = softirqs_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int __init proc_softirqs_init(void)
+{
+ proc_create("softirqs", 0, NULL, &proc_softirqs_operations);
+ return 0;
+}
+module_init(proc_softirqs_init);
diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 81904f0..74ac85a 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -25,6 +25,7 @@ static int show_stat(struct seq_file *p, void *v)
cputime64_t user, nice, system, idle, iowait, irq, softirq, steal;
cputime64_t guest;
u64 sum = 0;
+ u64 sum_softirq = 0;
struct timespec boottime;
unsigned int per_irq_sum;

@@ -49,6 +50,10 @@ static int show_stat(struct seq_file *p, void *v)
sum += kstat_irqs_cpu(j, i);

sum += arch_irq_stat_cpu(i);
+
+ for (j = 0; j < NR_SOFTIRQS; j++)
+ sum_softirq += kstat_softirqs_cpu(j, i);
+
}
sum += arch_irq_stat();

@@ -111,6 +116,18 @@ static int show_stat(struct seq_file *p, void *v)
nr_running(),
nr_iowait());

+ seq_printf(p, "softirq %llu", (unsigned long long)sum_softirq);
+
+ for (i = 0; i < NR_SOFTIRQS; i++) {
+ per_irq_sum = 0;
+
+ for_each_possible_cpu(j)
+ per_irq_sum += kstat_softirqs_cpu(i, j);
+
+ seq_printf(p, " %u", per_irq_sum);
+ }
+ seq_printf(p, "\n");
+
return 0;
}

--
1.5.0.6