From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f65.google.com ([74.125.83.65]:46123 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750980AbeBLHti (ORCPT ); Mon, 12 Feb 2018 02:49:38 -0500 Received: by mail-pg0-f65.google.com with SMTP id a11so7000141pgu.13 for ; Sun, 11 Feb 2018 23:49:38 -0800 (PST) From: Andrei Vagin To: linux-fsdevel@vger.kernel.org, Andrew Morton Cc: Alexey Dobriyan , Andrei Vagin Subject: [PATCH 4/4] proc: replace seq_printf by seq_put_smth to speed up /proc/pid/status Date: Sun, 11 Feb 2018 23:49:31 -0800 Message-Id: <20180212074931.7227-4-avagin@openvz.org> In-Reply-To: <20180212074931.7227-1-avagin@openvz.org> References: <20180212074931.7227-1-avagin@openvz.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: seq_printf() works slower than seq_puts, seq_puts, etc. == test_proc.c int main(int argc, char **argv) { int n, i, fd; char buf[16384]; n = atoi(argv[1]); for (i = 0; i < n; i++) { fd = open(argv[2], O_RDONLY); if (fd < 0) return 1; if (read(fd, buf, sizeof(buf)) <= 0) return 1; close(fd); } return 0; } == $ time ./test_proc 1000000 /proc/1/status == Before path == real 0m5.171s user 0m0.328s sys 0m4.783s == After patch == real 0m4.761s user 0m0.334s sys 0m4.366s Signed-off-by: Andrei Vagin --- fs/proc/array.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/fs/proc/array.c b/fs/proc/array.c index 598803576e4c..0a61affe1356 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -187,7 +187,8 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, task_unlock(p); rcu_read_unlock(); - seq_printf(m, "State:\t%s", get_task_state(p)); + seq_puts(m, "State:\t"); + seq_puts(m, get_task_state(p)); seq_put_decimal_ull(m, "\nTgid:\t", tgid); seq_put_decimal_ull(m, "\nNgid:\t", ngid); @@ -313,8 +314,8 @@ static void render_cap_t(struct seq_file *m, const char *header, seq_puts(m, header); CAP_FOR_EACH_U32(__capi) { - seq_printf(m, "%08x", - a->cap[CAP_LAST_U32 - __capi]); + seq_put_hex_ll(m, NULL, + a->cap[CAP_LAST_U32 - __capi], 8); } seq_putc(m, '\n'); } @@ -368,7 +369,8 @@ static void task_cpus_allowed(struct seq_file *m, struct task_struct *task) static inline void task_core_dumping(struct seq_file *m, struct mm_struct *mm) { - seq_printf(m, "CoreDumping:\t%d\n", !!mm->core_state); + seq_put_decimal_ull(m, "CoreDumping:\t", !!mm->core_state); + seq_putc(m, '\n'); } int proc_pid_status(struct seq_file *m, struct pid_namespace *ns, @@ -504,7 +506,11 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, /* convert nsec -> ticks */ start_time = nsec_to_clock_t(task->real_start_time); - seq_printf(m, "%d (%s) %c", pid_nr_ns(pid, ns), tcomm, state); + seq_put_decimal_ull(m, "", pid_nr_ns(pid, ns)); + seq_puts(m, " ("); + seq_puts(m, tcomm); + seq_puts(m, ") "); + seq_putc(m, state); seq_put_decimal_ll(m, " ", ppid); seq_put_decimal_ll(m, " ", pgid); seq_put_decimal_ll(m, " ", sid); -- 2.13.6