From: David Wang <00107082@163.com> Date: Wed, 6 Nov 2024 02:12:28 +0000 (+0800) Subject: proc/softirqs: replace seq_printf with seq_put_decimal_ull_width X-Git-Tag: v5.10.231~412 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e05e8f54d23f4dc404745d058bba3c92fe3d9d2e;p=thirdparty%2Fkernel%2Fstable.git proc/softirqs: replace seq_printf with seq_put_decimal_ull_width [ Upstream commit 84b9749a3a704dcc824a88aa8267247c801d51e4 ] seq_printf is costy, on a system with n CPUs, reading /proc/softirqs would yield 10*n decimal values, and the extra cost parsing format string grows linearly with number of cpus. Replace seq_printf with seq_put_decimal_ull_width have significant performance improvement. On an 8CPUs system, reading /proc/softirqs show ~40% performance gain with this patch. Signed-off-by: David Wang <00107082@163.com> Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- diff --git a/fs/proc/softirqs.c b/fs/proc/softirqs.c index 12901dcf57e2b..d8f4e7d54d002 100644 --- a/fs/proc/softirqs.c +++ b/fs/proc/softirqs.c @@ -19,7 +19,7 @@ static int show_softirqs(struct seq_file *p, void *v) for (i = 0; i < NR_SOFTIRQS; i++) { seq_printf(p, "%12s:", softirq_to_name[i]); for_each_possible_cpu(j) - seq_printf(p, " %10u", kstat_softirqs_cpu(i, j)); + seq_put_decimal_ull_width(p, " ", kstat_softirqs_cpu(i, j), 10); seq_putc(p, '\n'); } return 0;