Messages in this thread | | | Date | Thu, 20 Nov 2008 21:09:23 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH 2/3] proc: Export statistics for softirq to /proc |
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On Thu, 20 Nov 2008 19:58:43 -0800 Keika Kobayashi <kobayashi.kk@ncos.nec.co.jp> wrote:
> 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>
This all looks reasonable to me.
> fs/proc/Makefile | 1 + > fs/proc/softirqs.c | 57 +++++++++++++++++++++++++++++++++++++++++++++ > fs/proc/stat.c | 17 +++++++++++++ > include/linux/interrupt.h | 3 ++ > 4 files changed, 78 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..43d3bc0 > --- /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_online_cpu(i) > + seq_printf(p, "CPU%-8d", i); > + seq_printf(p, "\n"); > + > + for_each_softirq_nr(i) { > + seq_printf(p, "%-10s", desc_array[i]); > + for_each_online_cpu(j) > + seq_printf(p, "%10u ", kstat_softirqs_cpu(i, j)); > + seq_printf(p, "\n"); > + } > + return 0; > +}
This uses for_each_online_cpu(), but below we use for_each_possible_cpu().
Shouldn't we be consistent here so that at least the numbers will add up to the same thing?
Probably for_each_possible_cpu() is best - people might want to see how many softirqs happened on a CPU which was recently offlined.
> + > +static int softirqs_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, show_softirqs, NULL); > +} > + > +static struct file_operations proc_softirqs_operations = {
Make this const, please.
> + .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..02d5bf8 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_each_softirq_nr(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_each_softirq_nr(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; > } > > diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h > index f58a0cf..9a12ba0 100644 > --- a/include/linux/interrupt.h > +++ b/include/linux/interrupt.h > @@ -259,6 +259,9 @@ enum > NR_SOFTIRQS > }; > > +#define for_each_softirq_nr(irq) \ > + for (irq = 0; irq < NR_SOFTIRQS; irq++)
Can we remove this please? It doesn't make the code any more readable. Just open-code the loop at each site.
(And strictly speaking the `irq' macro arg should be parenthesised)
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