From: "tip-bot2 for Peter Zijlstra" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: sched/core] delayacct: Default disabled
Date: Wed, 12 May 2021 10:28:29 -0000 [thread overview]
Message-ID: <162081530906.29796.13536747995419262567.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20210505111525.308018373@infradead.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 <peterz@infradead.org>
AuthorDate: Tue, 04 May 2021 22:43:32 +02:00
Committer: Peter Zijlstra <peterz@infradead.org>
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) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
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 <linux/jump_label.h>
#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 <linux/delayacct.h>
#include <linux/module.h>
-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);
next prev parent reply other threads:[~2021-05-12 10:29 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-05 10:59 [PATCH 0/6] sched,delayacct: Some cleanups Peter Zijlstra
2021-05-05 10:59 ` [PATCH 1/6] delayacct: Use sched_clock() Peter Zijlstra
2021-05-05 14:40 ` Rik van Riel
2021-05-06 13:59 ` Johannes Weiner
2021-05-06 14:17 ` Peter Zijlstra
2021-05-06 15:17 ` Johannes Weiner
2021-05-07 12:40 ` Balbir Singh
2021-05-12 10:28 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-05-12 10:43 ` [PATCH 1/6] " Mel Gorman
2021-05-05 10:59 ` [PATCH 2/6] sched: Rename sched_info_{queued,dequeued} Peter Zijlstra
2021-05-05 14:39 ` Rik van Riel
2021-05-06 13:59 ` Johannes Weiner
2021-05-10 8:45 ` Balbir Singh
2021-05-12 10:28 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-05-12 10:49 ` [PATCH 2/6] " Mel Gorman
2021-05-05 10:59 ` [PATCH 3/6] sched: Simplify sched_info_on() Peter Zijlstra
2021-05-06 14:03 ` Johannes Weiner
2021-05-12 10:28 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-05-12 11:10 ` [PATCH 3/6] " Mel Gorman
2021-05-12 11:32 ` Peter Zijlstra
2021-05-12 12:51 ` Mel Gorman
2021-05-05 10:59 ` [PATCH 4/6] kvm: Select SCHED_INFO instead of TASK_DELAY_ACCT Peter Zijlstra
2021-05-05 11:37 ` Paolo Bonzini
2021-05-06 14:38 ` Marc Zyngier
2021-05-07 12:42 ` Balbir Singh
2021-05-12 10:28 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-05-12 11:11 ` [PATCH 4/6] " Mel Gorman
2021-05-05 10:59 ` [PATCH 5/6] delayacct: Add static_branch in scheduler hooks Peter Zijlstra
2021-05-06 14:05 ` Johannes Weiner
2021-05-10 8:42 ` Balbir Singh
2021-05-12 10:28 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-05-12 11:13 ` [PATCH 5/6] " Mel Gorman
2021-05-05 10:59 ` [PATCH 6/6] [RFC] delayacct: Default disabled Peter Zijlstra
2021-05-12 10:28 ` tip-bot2 for Peter Zijlstra [this message]
2021-05-12 11:35 ` Mel Gorman
2021-05-05 22:29 ` [PATCH 0/6] sched,delayacct: Some cleanups Balbir Singh
2021-05-06 9:13 ` Peter Zijlstra
2021-05-07 12:38 ` Balbir Singh
2021-05-12 11:34 ` Mel Gorman
2021-05-12 11:38 ` Peter Zijlstra
2021-05-12 12:23 ` Paul Wise
2021-05-12 13:00 ` Mel Gorman
2021-05-13 1:29 ` Paul Wise
2021-06-25 0:50 ` Paul Wise
2021-05-07 9:05 ` Thomas Gleixner
2021-05-10 7:08 ` Ingo Molnar
2021-05-10 12:05 ` [PATCH 7/6] delayacct: Add sysctl to enable at runtime Peter Zijlstra
2021-05-10 12:06 ` Peter Zijlstra
2021-05-12 10:28 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2021-05-12 11:40 ` [PATCH 7/6] " Mel Gorman
2021-05-19 8:09 ` [tip: sched/core] delayacct: Document task_delayacct sysctl tip-bot2 for Mel Gorman
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