The patch titled
proc: remove redundunt for_each_possible_cpu() loop
has been removed from the -mm tree. Its filename was
proc-export-statistics-for-softirq-to-proc-fix.patch
This patch was dropped because it was folded into proc-export-statistics-for-softirq-to-proc.patch
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: proc: remove redundunt for_each_possible_cpu() loop
From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Distros will set NR_CPUS to very large number and at that time
for_each_possible_cpu() is a bit costly.
Therefore, To remove unnecessary twice loop is better.
Note. we can remove softirq's redundunt loop, but we can't remove irq's.
because NR_SOFTIRQS ~= 10, NR_IRQS ~= 4000 (in x86 case).
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Keika Kobayashi <kobayashi.kk@xxxxxxxxxxxxxx>
Cc: Hiroshi Shimamoto <h-shimamoto@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Eric Dumazet <dada1@xxxxxxxxxxxxx>
Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/stat.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff -puN fs/proc/stat.c~proc-export-statistics-for-softirq-to-proc-fix fs/proc/stat.c
--- a/fs/proc/stat.c~proc-export-statistics-for-softirq-to-proc-fix
+++ a/fs/proc/stat.c
@@ -27,6 +27,7 @@ static int show_stat(struct seq_file *p,
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;
@@ -51,8 +52,12 @@ static int show_stat(struct seq_file *p,
}
sum += arch_irq_stat_cpu(i);
- for (j = 0; j < NR_SOFTIRQS; j++)
- sum_softirq += kstat_softirqs_cpu(j, 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();
@@ -118,12 +123,7 @@ static int show_stat(struct seq_file *p,
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, " %u", per_softirq_sums[i]);
}
seq_printf(p, "\n");
_
Patches currently in -mm which might be from kosaki.motohiro@xxxxxxxxxxxxxx are
origin.patch
linux-next.patch
mm-update_page_reclaim_stat-is-called-from-page-fault-path.patch
getrusage-fill-ru_maxrss-value.patch
softirq-introduce-statistics-for-softirq.patch
proc-export-statistics-for-softirq-to-proc.patch
proc-export-statistics-for-softirq-to-proc-fix.patch
proc-update-document-for-proc-softirqs-and-proc-stat.patch
memcg-remove-mem_cgroup_calc_mapped_ratio-take2.patch
memcg-remove-mem_cgroup_reclaim_imbalance-remnants.patch
ia64-implement-interrupt-enabling-rwlocks.patch
fs-symlink-write_begin-allocation-context-fix-reiser4-fix.patch
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