From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DA23CC5B57D for ; Mon, 8 Jul 2019 06:01:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BDC2620659 for ; Mon, 8 Jul 2019 06:01:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728879AbfGHGBD (ORCPT ); Mon, 8 Jul 2019 02:01:03 -0400 Received: from lgeamrelo11.lge.com ([156.147.23.51]:37352 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728075AbfGHGBD (ORCPT ); Mon, 8 Jul 2019 02:01:03 -0400 Received: from unknown (HELO lgeamrelo02.lge.com) (156.147.1.126) by 156.147.23.51 with ESMTP; 8 Jul 2019 15:01:01 +0900 X-Original-SENDERIP: 156.147.1.126 X-Original-MAILFROM: byungchul.park@lge.com Received: from unknown (HELO localhost.localdomain) (10.177.222.33) by 156.147.1.126 with ESMTP; 8 Jul 2019 15:01:01 +0900 X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com From: Byungchul Park To: paulmck@linux.ibm.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@lge.com Subject: [PATCH] rcu: Make jiffies_till_sched_qs writable Date: Mon, 8 Jul 2019 15:00:09 +0900 Message-Id: <1562565609-12482-1-git-send-email-byungchul.park@lge.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org jiffies_till_sched_qs is useless if it's readonly as it is used to set jiffies_to_sched_qs with its value regardless of first/next fqs jiffies. And it should be applied immediately on change through sysfs. The function for setting jiffies_to_sched_qs, adjust_jiffies_till_sched_qs() will be called only if the value from sysfs != ULONG_MAX. And the value won't be adjusted unlike first/next fqs jiffies. While at it, changed the positions of two module_param()s downward. Signed-off-by: Byungchul Park --- kernel/rcu/tree.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index a2f8ba2..a28e2fe 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -422,9 +422,7 @@ static int rcu_is_cpu_rrupt_from_idle(void) * quiescent-state help from rcu_note_context_switch(). */ static ulong jiffies_till_sched_qs = ULONG_MAX; -module_param(jiffies_till_sched_qs, ulong, 0444); static ulong jiffies_to_sched_qs; /* See adjust_jiffies_till_sched_qs(). */ -module_param(jiffies_to_sched_qs, ulong, 0444); /* Display only! */ /* * Make sure that we give the grace-period kthread time to detect any @@ -450,6 +448,18 @@ static void adjust_jiffies_till_sched_qs(void) WRITE_ONCE(jiffies_to_sched_qs, j); } +static int param_set_sched_qs_jiffies(const char *val, const struct kernel_param *kp) +{ + ulong j; + int ret = kstrtoul(val, 0, &j); + + if (!ret && j != ULONG_MAX) { + WRITE_ONCE(*(ulong *)kp->arg, j); + adjust_jiffies_till_sched_qs(); + } + return ret; +} + static int param_set_first_fqs_jiffies(const char *val, const struct kernel_param *kp) { ulong j; @@ -474,6 +484,11 @@ static int param_set_next_fqs_jiffies(const char *val, const struct kernel_param return ret; } +static struct kernel_param_ops sched_qs_jiffies_ops = { + .set = param_set_sched_qs_jiffies, + .get = param_get_ulong, +}; + static struct kernel_param_ops first_fqs_jiffies_ops = { .set = param_set_first_fqs_jiffies, .get = param_get_ulong, @@ -484,8 +499,11 @@ static int param_set_next_fqs_jiffies(const char *val, const struct kernel_param .get = param_get_ulong, }; +module_param_cb(jiffies_till_sched_qs, &sched_qs_jiffies_ops, &jiffies_till_sched_qs, 0644); module_param_cb(jiffies_till_first_fqs, &first_fqs_jiffies_ops, &jiffies_till_first_fqs, 0644); module_param_cb(jiffies_till_next_fqs, &next_fqs_jiffies_ops, &jiffies_till_next_fqs, 0644); + +module_param(jiffies_to_sched_qs, ulong, 0444); /* Display only! */ module_param(rcu_kick_kthreads, bool, 0644); static void force_qs_rnp(int (*f)(struct rcu_data *rdp)); -- 1.9.1