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 B6A72C433ED for ; Wed, 12 May 2021 10:29:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 824A161106 for ; Wed, 12 May 2021 10:29:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230467AbhELKau (ORCPT ); Wed, 12 May 2021 06:30:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230429AbhELK3j (ORCPT ); Wed, 12 May 2021 06:29:39 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30B55C061761; Wed, 12 May 2021 03:28:31 -0700 (PDT) Date: Wed, 12 May 2021 10:28:29 -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=UsqZZgvV69PndNSLGVX4JrpPPoDgX5xNdwYhxEOJtXI=; b=XCz4INBdA7M33eGvqPEGDbP2Gs+0W5cyiUPFPr5tCMwL2JETib1m25xblJFSJA2MQR0uAq YLNwTzhDNYtKg2qap4W00lHaqlm8FLgjuD95lqXuJhxDObvQMuX+WcpkC3b5syeOV2jiO/ 3QNOqTGLCVAgKFe9cgaSBOaKsiPY6glK2gC7mavTIy3zQTAfszjN5NYMU42xdk1ENjB2nG kdotRwHZvhR1mSHz4lWJvpphjzmLRY58d1sESw9QgwT7lI4vLLQWOBYT0jh0Ba4rlxu2uB W4XQx4hdJPdxA8e5UXrtGOEt+C5AgbOzERwvPlFdZDr80ddx/qovj3znJ8oFKg== 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=UsqZZgvV69PndNSLGVX4JrpPPoDgX5xNdwYhxEOJtXI=; b=UfopozyMsv3T+360EziQDhUH3OzoNfTJWuN+zRl/EdevuJd3Uc+H6Ssk4VrAaZlkj3ZojK b6t1bGyStgqSN+AQ== 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: Default disabled Cc: "Peter Zijlstra (Intel)" , Thomas Gleixner , Ingo Molnar , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20210505111525.308018373@infradead.org> References: <20210505111525.308018373@infradead.org> MIME-Version: 1.0 Message-ID: <162081530906.29796.13536747995419262567.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: e4042ad492357fa995921376462b04a025dd53b6 Gitweb: https://git.kernel.org/tip/e4042ad492357fa995921376462b04a025dd53b6 Author: Peter Zijlstra AuthorDate: Tue, 04 May 2021 22:43:32 +02:00 Committer: Peter Zijlstra CommitterDate: Wed, 12 May 2021 11:43:25 +02:00 delayacct: Default disabled Assuming this stuff isn't actually used much; disable it by default and avoid allocating and tracking the task_delay_info structure. taskstats is changed to still report the regular sched and sched_info and only skip the missing task_delay_info fields instead of not reporting anything. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Thomas Gleixner Reviewed-by: Ingo Molnar Link: https://lkml.kernel.org/r/20210505111525.308018373@infradead.org --- Documentation/accounting/delay-accounting.rst | 8 +++---- Documentation/admin-guide/kernel-parameters.txt | 2 +- include/linux/delayacct.h | 16 +++---------- kernel/delayacct.c | 19 +++++++++------- 4 files changed, 20 insertions(+), 25 deletions(-) diff --git a/Documentation/accounting/delay-accounting.rst b/Documentation/accounting/delay-accounting.rst index 7cc7f58..f20b282 100644 --- a/Documentation/accounting/delay-accounting.rst +++ b/Documentation/accounting/delay-accounting.rst @@ -69,13 +69,13 @@ Compile the kernel with:: CONFIG_TASK_DELAY_ACCT=y CONFIG_TASKSTATS=y -Delay accounting is enabled by default at boot up. -To disable, add:: +Delay accounting is disabled by default at boot up. +To enable, add:: - nodelayacct + delayacct to the kernel boot options. The rest of the instructions -below assume this has not been done. +below assume this has been done. After the system has booted up, use a utility similar to getdelays.c to access the delays diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index cb89dbd..ef5048c 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3244,7 +3244,7 @@ noclflush [BUGS=X86] Don't use the CLFLUSH instruction - nodelayacct [KNL] Disable per-task delay accounting + delayacct [KNL] Enable per-task delay accounting nodsp [SH] Disable hardware DSP at boot time. diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h index 57fefa5..225c8e0 100644 --- a/include/linux/delayacct.h +++ b/include/linux/delayacct.h @@ -61,7 +61,7 @@ struct task_delay_info { #include #ifdef CONFIG_TASK_DELAY_ACCT -DECLARE_STATIC_KEY_TRUE(delayacct_key); +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); @@ -69,7 +69,7 @@ extern void __delayacct_tsk_init(struct task_struct *); extern void __delayacct_tsk_exit(struct task_struct *); extern void __delayacct_blkio_start(void); extern void __delayacct_blkio_end(struct task_struct *); -extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *); +extern int delayacct_add_tsk(struct taskstats *, struct task_struct *); extern __u64 __delayacct_blkio_ticks(struct task_struct *); extern void __delayacct_freepages_start(void); extern void __delayacct_freepages_end(void); @@ -116,7 +116,7 @@ static inline void delayacct_tsk_free(struct task_struct *tsk) static inline void delayacct_blkio_start(void) { - if (!static_branch_likely(&delayacct_key)) + if (!static_branch_unlikely(&delayacct_key)) return; delayacct_set_flag(current, DELAYACCT_PF_BLKIO); @@ -126,7 +126,7 @@ static inline void delayacct_blkio_start(void) static inline void delayacct_blkio_end(struct task_struct *p) { - if (!static_branch_likely(&delayacct_key)) + if (!static_branch_unlikely(&delayacct_key)) return; if (p->delays) @@ -134,14 +134,6 @@ static inline void delayacct_blkio_end(struct task_struct *p) delayacct_clear_flag(p, DELAYACCT_PF_BLKIO); } -static inline int delayacct_add_tsk(struct taskstats *d, - struct task_struct *tsk) -{ - if (!delayacct_on || !tsk->delays) - return 0; - return __delayacct_add_tsk(d, tsk); -} - static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk) { if (tsk->delays) diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 63012fd..3f08690 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -14,23 +14,23 @@ #include #include -DEFINE_STATIC_KEY_TRUE(delayacct_key); -int delayacct_on __read_mostly = 1; /* Delay accounting turned on/off */ +DEFINE_STATIC_KEY_FALSE(delayacct_key); +int delayacct_on __read_mostly; /* Delay accounting turned on/off */ struct kmem_cache *delayacct_cache; -static int __init delayacct_setup_disable(char *str) +static int __init delayacct_setup_enable(char *str) { - delayacct_on = 0; + delayacct_on = 1; return 1; } -__setup("nodelayacct", delayacct_setup_disable); +__setup("delayacct", delayacct_setup_enable); 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_disable(&delayacct_key); + if (delayacct_on) + static_branch_enable(&delayacct_key); } void __delayacct_tsk_init(struct task_struct *tsk) @@ -83,7 +83,7 @@ void __delayacct_blkio_end(struct task_struct *p) delayacct_end(&delays->lock, &delays->blkio_start, total, count); } -int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) +int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) { u64 utime, stime, stimescaled, utimescaled; unsigned long long t2, t3; @@ -118,6 +118,9 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) d->cpu_run_virtual_total = (tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp; + if (!tsk->delays) + return 0; + /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */ raw_spin_lock_irqsave(&tsk->delays->lock, flags);