Commit d3d64df2 authored by Keika Kobayashi's avatar Keika Kobayashi Committed by Linus Torvalds
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proc: export statistics for softirq to /proc 



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.

[kosaki.motohiro@jp.fujitsu.com: remove redundant for_each_possible_cpu() loop]
Signed-off-by: default avatarKeika Kobayashi <kobayashi.kk@ncos.nec.co.jp>
Reviewed-by: default avatarHiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9d9b8fb0

Documentation/filesystems/proc.txt

+26 −0
Original line number Diff line number Diff line
@@ -283,6 +283,7 @@ Table 1-4: Kernel info in /proc 
 rtc         Real time clock                                   

 scsi        SCSI info (see text)                              

 slabinfo    Slab pool info                                    

 softirqs    softirq usage

 stat        Overall statistics                                

 swaps       Swap space utilization                            

 sys         See chapter 2
@@ -597,6 +598,25 @@ on the kind of area : 
0xffffffffa0017000-0xffffffffa0022000   45056 sys_init_module+0xc27/0x1d00 ...

   pages=10 vmalloc N0=10



..............................................................................



softirqs:



Provides counts of softirq handlers serviced since boot time, for each cpu.



> cat /proc/softirqs

                CPU0       CPU1       CPU2       CPU3

      HI:          0          0          0          0

   TIMER:      27166      27120      27097      27034

  NET_TX:          0          0          0         17

  NET_RX:         42          0          0         39

   BLOCK:          0          0        107       1121

 TASKLET:          0          0          0        290

   SCHED:      27035      26983      26971      26746

 HRTIMER:          0          0          0          0

     RCU:       1678       1769       2178       2250





1.3 IDE devices in /proc/ide

----------------------------
@@ -883,6 +903,7 @@ since the system first booted. For a quick look, simply cat the file: 
  processes 2915

  procs_running 1

  procs_blocked 0

  softirq 183433 0 21755 12 39 1137 231 21459 2263



The very first  "cpu" line aggregates the  numbers in all  of the other "cpuN"

lines.  These numbers identify the amount of time the CPU has spent performing
@@ -918,6 +939,11 @@ CPUs. 
The   "procs_blocked" line gives  the  number of  processes currently blocked,

waiting for I/O to complete.



The "softirq" line gives counts of softirqs serviced since boot time, for each

of the possible system softirqs. The first column is the total of all

softirqs serviced; each subsequent column is the total for that particular

softirq.





1.9 Ext4 file system parameters

------------------------------

fs/proc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -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

fs/proc/softirqs.c

0 → 100644
+44 −0
Original line number Diff line number Diff line 
#include <linux/init.h>

#include <linux/kernel_stat.h>

#include <linux/proc_fs.h>

#include <linux/seq_file.h>



/*

 * /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, "%8s:", softirq_to_name[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);

fs/proc/stat.c

+15 −0
Original line number Diff line number Diff line
@@ -29,6 +29,8 @@ 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;

	unsigned int per_softirq_sums[NR_SOFTIRQS] = {0};

	struct timespec boottime;

	unsigned int per_irq_sum;
@@ -53,6 +55,13 @@ 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++) {

			unsigned int softirq_stat = kstat_softirqs_cpu(j, i);



			per_softirq_sums[j] += softirq_stat;

			sum_softirq += softirq_stat;

		}

	}

	sum += arch_irq_stat();
@@ -115,6 +124,12 @@ 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++)

		seq_printf(p, " %u", per_softirq_sums[i]);

	seq_printf(p, "\n");



	return 0;

}

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