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=-20.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 EC1F1C433B4 for ; Wed, 12 May 2021 10:29:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B50CB613FB for ; Wed, 12 May 2021 10:29:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231335AbhELKao (ORCPT ); Wed, 12 May 2021 06:30:44 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:50544 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230398AbhELK3i (ORCPT ); Wed, 12 May 2021 06:29:38 -0400 Date: Wed, 12 May 2021 10:28:28 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1620815309; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xQBquYpW0oCpypwgTS9JGzv1AQJSSjvg3kcverQPfPQ=; b=KJbr+L6/Cn4cHTXHNS8F/+zkZ95H7SUpICnXWLmM4RtG0pbbXf5WMA5EpYszILlU6SlhTS /j3eI9AKrw2kLbRv0C62hE2uGDq/LgMa174UF+vxOjyXrBG0JVRx3AriYcgyGDjkFQyYT+ G9d2SPNhtIf+L/GXBpuum82P3sjibYKE2D0tWI2m+oLGdZNCFn9ERlqZh+uIH/oolMIrX2 HAgc2S1v2VnPGXCVZ0IeYhbqT0RyhMvG7lV3K1F8JJqDuk50+viLpSlirl0INmNGMCrBdC b02yvCLoRWFf9j2ZjXHf1M0FqfBwxECcVzsDCaxkQ17eJlkM/6UbKgZrjH+cDg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1620815309; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=xQBquYpW0oCpypwgTS9JGzv1AQJSSjvg3kcverQPfPQ=; b=wsN5Oui7BTbYA+g0vTa3xzVHCj2rtK0v2mqBucV1A4fjpQwpfxaTjE2y8QAcN38sS5ShHZ rk511HCVNcHWi4Ag== From: "tip-bot2 for Peter Zijlstra" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/core] delayacct: Add sysctl to enable at runtime Cc: "Peter Zijlstra (Intel)" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: References: MIME-Version: 1.0 Message-ID: <162081530866.29796.12022086349139308604.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the sched/core branch of tip: Commit-ID: 0cd7c741f01de13dc1eecf22557593b3514639bb Gitweb: https://git.kernel.org/tip/0cd7c741f01de13dc1eecf22557593b3514639bb Author: Peter Zijlstra AuthorDate: Mon, 10 May 2021 14:01:00 +02:00 Committer: Peter Zijlstra CommitterDate: Wed, 12 May 2021 11:43:25 +02:00 delayacct: Add sysctl to enable at runtime Just like sched_schedstats, allow runtime enabling (and disabling) of delayacct. This is useful if one forgot to add the delayacct boot time option. Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/YJkhebGJAywaZowX@hirez.programming.kicks-ass.net --- Documentation/accounting/delay-accounting.rst | 6 ++- include/linux/delayacct.h | 4 ++- kernel/delayacct.c | 36 +++++++++++++++++- kernel/sysctl.c | 12 ++++++- 4 files changed, 54 insertions(+), 4 deletions(-) diff --git a/Documentation/accounting/delay-accounting.rst b/Documentation/accounting/delay-accounting.rst index f20b282..1b8b46d 100644 --- a/Documentation/accounting/delay-accounting.rst +++ b/Documentation/accounting/delay-accounting.rst @@ -74,8 +74,10 @@ To enable, add:: delayacct -to the kernel boot options. The rest of the instructions -below assume this has been done. +to the kernel boot options. The rest of the instructions below assume this has +been done. Alternatively, use sysctl kernel.task_delayacct to switch the state +at runtime. Note however that only tasks started after enabling it will have +delayacct information. After the system has booted up, use a utility similar to getdelays.c to access the delays diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h index 225c8e0..af7e6eb 100644 --- a/include/linux/delayacct.h +++ b/include/linux/delayacct.h @@ -65,6 +65,10 @@ DECLARE_STATIC_KEY_FALSE(delayacct_key); extern int delayacct_on; /* Delay accounting turned on/off */ extern struct kmem_cache *delayacct_cache; extern void delayacct_init(void); + +extern int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos); + extern void __delayacct_tsk_init(struct task_struct *); extern void __delayacct_tsk_exit(struct task_struct *); extern void __delayacct_blkio_start(void); diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 3f08690..51530d5 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -18,6 +18,17 @@ DEFINE_STATIC_KEY_FALSE(delayacct_key); int delayacct_on __read_mostly; /* Delay accounting turned on/off */ struct kmem_cache *delayacct_cache; +static void set_delayacct(bool enabled) +{ + if (enabled) { + static_branch_enable(&delayacct_key); + delayacct_on = 1; + } else { + delayacct_on = 0; + static_branch_disable(&delayacct_key); + } +} + static int __init delayacct_setup_enable(char *str) { delayacct_on = 1; @@ -29,9 +40,30 @@ void delayacct_init(void) { delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC|SLAB_ACCOUNT); delayacct_tsk_init(&init_task); - if (delayacct_on) - static_branch_enable(&delayacct_key); + set_delayacct(delayacct_on); +} + +#ifdef CONFIG_PROC_SYSCTL +int sysctl_delayacct(struct ctl_table *table, int write, void *buffer, + size_t *lenp, loff_t *ppos) +{ + int state = delayacct_on; + struct ctl_table t; + int err; + + if (write && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + t = *table; + t.data = &state; + err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); + if (err < 0) + return err; + if (write) + set_delayacct(state); + return err; } +#endif void __delayacct_tsk_init(struct task_struct *tsk) { diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 14edf84..0afbfc8 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -71,6 +71,7 @@ #include #include #include +#include #include "../lib/kstrtox.h" @@ -1727,6 +1728,17 @@ static struct ctl_table kern_table[] = { .extra2 = SYSCTL_ONE, }, #endif /* CONFIG_SCHEDSTATS */ +#ifdef CONFIG_TASK_DELAY_ACCT + { + .procname = "task_delayacct", + .data = NULL, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = sysctl_delayacct, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, +#endif /* CONFIG_TASK_DELAY_ACCT */ #ifdef CONFIG_NUMA_BALANCING { .procname = "numa_balancing",