| Message ID | 1546873978-27797-2-git-send-email-longman@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | /proc/stat: Reduce irqs counting performance overhead | expand |
On Mon, Jan 7, 2019 at 7:13 AM Waiman Long <longman@redhat.com> wrote: > > The code that generates the "intr" line of /proc/stat is now moved > from show_stat() into a new function - show_stat_irqs(). There is no > functional change. > > Signed-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Kees Cook <keescook@chromium.org> -Kees > --- > fs/proc/stat.c | 39 +++++++++++++++++++++++++++++---------- > 1 file changed, 29 insertions(+), 10 deletions(-) > > diff --git a/fs/proc/stat.c b/fs/proc/stat.c > index 535eda7..4b06f1b 100644 > --- a/fs/proc/stat.c > +++ b/fs/proc/stat.c > @@ -79,12 +79,38 @@ static u64 get_iowait_time(int cpu) > > #endif > > +static u64 compute_stat_irqs_sum(void) > +{ > + int i; > + u64 sum = 0; > + > + for_each_possible_cpu(i) { > + sum += kstat_cpu_irqs_sum(i); > + sum += arch_irq_stat_cpu(i); > + } > + sum += arch_irq_stat(); > + return sum; > +} > + > +/* > + * Print out the "intr" line of /proc/stat. > + */ > +static void show_stat_irqs(struct seq_file *p) > +{ > + int i; > + > + seq_put_decimal_ull(p, "intr ", compute_stat_irqs_sum()); > + for_each_irq_nr(i) > + seq_put_decimal_ull(p, " ", kstat_irqs_usr(i)); > + > + seq_putc(p, '\n'); > +} > + > static int show_stat(struct seq_file *p, void *v) > { > 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; > @@ -105,8 +131,6 @@ static int show_stat(struct seq_file *p, void *v) > steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL]; > guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST]; > guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE]; > - sum += kstat_cpu_irqs_sum(i); > - sum += arch_irq_stat_cpu(i); > > for (j = 0; j < NR_SOFTIRQS; j++) { > unsigned int softirq_stat = kstat_softirqs_cpu(j, i); > @@ -115,7 +139,6 @@ static int show_stat(struct seq_file *p, void *v) > sum_softirq += softirq_stat; > } > } > - 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)); > @@ -154,14 +177,10 @@ static int show_stat(struct seq_file *p, void *v) > seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice)); > seq_putc(p, '\n'); > } > - seq_put_decimal_ull(p, "intr ", (unsigned long long)sum); > - > - /* sum again ? it could be updated? */ > - for_each_irq_nr(j) > - seq_put_decimal_ull(p, " ", kstat_irqs_usr(j)); > + show_stat_irqs(p); > > seq_printf(p, > - "\nctxt %llu\n" > + "ctxt %llu\n" > "btime %llu\n" > "processes %lu\n" > "procs_running %lu\n" > -- > 1.8.3.1 >
diff --git a/fs/proc/stat.c b/fs/proc/stat.c index 535eda7..4b06f1b 100644 --- a/fs/proc/stat.c +++ b/fs/proc/stat.c @@ -79,12 +79,38 @@ static u64 get_iowait_time(int cpu) #endif +static u64 compute_stat_irqs_sum(void) +{ + int i; + u64 sum = 0; + + for_each_possible_cpu(i) { + sum += kstat_cpu_irqs_sum(i); + sum += arch_irq_stat_cpu(i); + } + sum += arch_irq_stat(); + return sum; +} + +/* + * Print out the "intr" line of /proc/stat. + */ +static void show_stat_irqs(struct seq_file *p) +{ + int i; + + seq_put_decimal_ull(p, "intr ", compute_stat_irqs_sum()); + for_each_irq_nr(i) + seq_put_decimal_ull(p, " ", kstat_irqs_usr(i)); + + seq_putc(p, '\n'); +} + static int show_stat(struct seq_file *p, void *v) { 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; @@ -105,8 +131,6 @@ static int show_stat(struct seq_file *p, void *v) steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL]; guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST]; guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE]; - sum += kstat_cpu_irqs_sum(i); - sum += arch_irq_stat_cpu(i); for (j = 0; j < NR_SOFTIRQS; j++) { unsigned int softirq_stat = kstat_softirqs_cpu(j, i); @@ -115,7 +139,6 @@ static int show_stat(struct seq_file *p, void *v) sum_softirq += softirq_stat; } } - 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)); @@ -154,14 +177,10 @@ static int show_stat(struct seq_file *p, void *v) seq_put_decimal_ull(p, " ", nsec_to_clock_t(guest_nice)); seq_putc(p, '\n'); } - seq_put_decimal_ull(p, "intr ", (unsigned long long)sum); - - /* sum again ? it could be updated? */ - for_each_irq_nr(j) - seq_put_decimal_ull(p, " ", kstat_irqs_usr(j)); + show_stat_irqs(p); seq_printf(p, - "\nctxt %llu\n" + "ctxt %llu\n" "btime %llu\n" "processes %lu\n" "procs_running %lu\n"
The code that generates the "intr" line of /proc/stat is now moved from show_stat() into a new function - show_stat_irqs(). There is no functional change. Signed-off-by: Waiman Long <longman@redhat.com> --- fs/proc/stat.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-)