LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Frederic Weisbecker <frederic@kernel.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Frederic Weisbecker <frederic@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Chris Metcalf <cmetcalf@mellanox.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Luiz Capitulino <lcapitulino@redhat.com>,
	Christoph Lameter <cl@linux.com>,
	"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
	Mike Galbraith <efault@gmx.de>, Rik van Riel <riel@redhat.com>,
	Wanpeng Li <kernellwp@gmail.com>
Subject: [PATCH 08/12] housekeeping: Introduce housekeeping flags
Date: Fri, 27 Oct 2017 04:42:35 +0200
Message-ID: <1509072159-31808-9-git-send-email-frederic@kernel.org> (raw)
In-Reply-To: <1509072159-31808-1-git-send-email-frederic@kernel.org>

Before we implement isolcpus under housekeeping, we need the isolation
features to be more finegrained. For example some people want nohz_full
without the full scheduler isolation, others want full scheduler
isolation without nohz_full.

So let's cut all these isolation features piecewise, at the risk of
overcutting it right now. We can still merge some flags later if they
always make sense together.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <kernellwp@gmail.com>
---
 drivers/net/ethernet/tile/tilegx.c |  4 ++--
 include/linux/sched/isolation.h    | 26 +++++++++++++++++---------
 kernel/rcu/tree_plugin.h           |  2 +-
 kernel/rcu/update.c                |  2 +-
 kernel/sched/core.c                |  8 ++++----
 kernel/sched/fair.c                |  2 +-
 kernel/sched/isolation.c           | 26 +++++++++++++++-----------
 kernel/watchdog.c                  |  3 ++-
 8 files changed, 43 insertions(+), 30 deletions(-)

diff --git a/drivers/net/ethernet/tile/tilegx.c b/drivers/net/ethernet/tile/tilegx.c
index 27a3272..b3e5816 100644
--- a/drivers/net/ethernet/tile/tilegx.c
+++ b/drivers/net/ethernet/tile/tilegx.c
@@ -2270,8 +2270,8 @@ static int __init tile_net_init_module(void)
 		tile_net_dev_init(name, mac);
 
 	if (!network_cpus_init())
-		cpumask_and(&network_cpus_map, housekeeping_cpumask(),
-			    cpu_online_mask);
+		cpumask_and(&network_cpus_map,
+			    housekeeping_cpumask(HK_FLAG_MISC), cpu_online_mask);
 
 	return 0;
 }
diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h
index 93ac2367..9bb753e 100644
--- a/include/linux/sched/isolation.h
+++ b/include/linux/sched/isolation.h
@@ -5,35 +5,43 @@
 #include <linux/init.h>
 #include <linux/tick.h>
 
+enum hk_flags {
+	HK_FLAG_TIMER		= 1,
+	HK_FLAG_RCU		= (1 << 1),
+	HK_FLAG_MISC		= (1 << 2),
+	HK_FLAG_SCHED		= (1 << 3),
+};
+
 #ifdef CONFIG_CPU_ISOLATION
 DECLARE_STATIC_KEY_FALSE(housekeeping_overriden);
-extern int housekeeping_any_cpu(void);
-extern const struct cpumask *housekeeping_cpumask(void);
-extern void housekeeping_affine(struct task_struct *t);
-extern bool housekeeping_test_cpu(int cpu);
+extern int housekeeping_any_cpu(enum hk_flags flags);
+extern const struct cpumask *housekeeping_cpumask(enum hk_flags flags);
+extern void housekeeping_affine(struct task_struct *t, enum hk_flags flags);
+extern bool housekeeping_test_cpu(int cpu, enum hk_flags flags);
 extern void __init housekeeping_init(void);
 
 #else
 
-static inline int housekeeping_any_cpu(void)
+static inline int housekeeping_any_cpu(enum hk_flags flags)
 {
 	return smp_processor_id();
 }
 
-static inline const struct cpumask *housekeeping_cpumask(void)
+static inline const struct cpumask *housekeeping_cpumask(enum hk_flags flags)
 {
 	return cpu_possible_mask;
 }
 
-static inline void housekeeping_affine(struct task_struct *t) { }
+static inline void housekeeping_affine(struct task_struct *t,
+				       enum hk_flags flags) { }
 static inline void housekeeping_init(void) { }
 #endif /* CONFIG_CPU_ISOLATION */
 
-static inline bool housekeeping_cpu(int cpu)
+static inline bool housekeeping_cpu(int cpu, enum hk_flags flags)
 {
 #ifdef CONFIG_CPU_ISOLATION
 	if (static_branch_unlikely(&housekeeping_overriden))
-		return housekeeping_test_cpu(cpu);
+		return housekeeping_test_cpu(cpu, flags);
 #endif
 	return true;
 }
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index c7632f5..34125d2 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -2584,7 +2584,7 @@ static void rcu_bind_gp_kthread(void)
 
 	if (!tick_nohz_full_enabled())
 		return;
-	housekeeping_affine(current);
+	housekeeping_affine(current, HK_FLAG_RCU);
 }
 
 /* Record the current task on dyntick-idle entry. */
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index 79abeb0..e3e60ef 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -719,7 +719,7 @@ static int __noreturn rcu_tasks_kthread(void *arg)
 	LIST_HEAD(rcu_tasks_holdouts);
 
 	/* Run on housekeeping CPUs by default.  Sysadm can move if desired. */
-	housekeeping_affine(current);
+	housekeeping_affine(current, HK_FLAG_RCU);
 
 	/*
 	 * Each pass through the following loop makes one check for
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d0fb448d..2210c02 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -527,7 +527,7 @@ int get_nohz_timer_target(void)
 	int i, cpu = smp_processor_id();
 	struct sched_domain *sd;
 
-	if (!idle_cpu(cpu) && housekeeping_cpu(cpu))
+	if (!idle_cpu(cpu) && housekeeping_cpu(cpu, HK_FLAG_TIMER))
 		return cpu;
 
 	rcu_read_lock();
@@ -536,15 +536,15 @@ int get_nohz_timer_target(void)
 			if (cpu == i)
 				continue;
 
-			if (!idle_cpu(i) && housekeeping_cpu(i)) {
+			if (!idle_cpu(i) && housekeeping_cpu(i, HK_FLAG_TIMER)) {
 				cpu = i;
 				goto unlock;
 			}
 		}
 	}
 
-	if (!housekeeping_cpu(cpu))
-		cpu = housekeeping_any_cpu();
+	if (!housekeeping_cpu(cpu, HK_FLAG_TIMER))
+		cpu = housekeeping_any_cpu(HK_FLAG_TIMER);
 unlock:
 	rcu_read_unlock();
 	return cpu;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index cdece8f..f755de8 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9027,7 +9027,7 @@ void nohz_balance_enter_idle(int cpu)
 		return;
 
 	/* Spare idle load balancing on CPUs that don't want to be disturbed: */
-	if (!housekeeping_cpu(cpu))
+	if (!housekeeping_cpu(cpu, HK_FLAG_SCHED))
 		return;
 
 	if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index bb8ba19..37a138a 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -15,37 +15,39 @@
 DEFINE_STATIC_KEY_FALSE(housekeeping_overriden);
 EXPORT_SYMBOL_GPL(housekeeping_overriden);
 static cpumask_var_t housekeeping_mask;
+static unsigned int housekeeping_flags;
 
-int housekeeping_any_cpu(void)
+int housekeeping_any_cpu(enum hk_flags flags)
 {
 	if (static_branch_unlikely(&housekeeping_overriden))
-		return cpumask_any_and(housekeeping_mask, cpu_online_mask);
-
+		if (housekeeping_flags & flags)
+			return cpumask_any_and(housekeeping_mask, cpu_online_mask);
 	return smp_processor_id();
 }
 EXPORT_SYMBOL_GPL(housekeeping_any_cpu);
 
-const struct cpumask *housekeeping_cpumask(void)
+const struct cpumask *housekeeping_cpumask(enum hk_flags flags)
 {
 	if (static_branch_unlikely(&housekeeping_overriden))
-		return housekeeping_mask;
-
+		if (housekeeping_flags & flags)
+			return housekeeping_mask;
 	return cpu_possible_mask;
 }
 EXPORT_SYMBOL_GPL(housekeeping_cpumask);
 
-void housekeeping_affine(struct task_struct *t)
+void housekeeping_affine(struct task_struct *t, enum hk_flags flags)
 {
 	if (static_branch_unlikely(&housekeeping_overriden))
-		set_cpus_allowed_ptr(t, housekeeping_mask);
+		if (housekeeping_flags & flags)
+			set_cpus_allowed_ptr(t, housekeeping_mask);
 }
 EXPORT_SYMBOL_GPL(housekeeping_affine);
 
-bool housekeeping_test_cpu(int cpu)
+bool housekeeping_test_cpu(int cpu, enum hk_flags flags)
 {
 	if (static_branch_unlikely(&housekeeping_overriden))
-		return cpumask_test_cpu(cpu, housekeeping_mask);
-
+		if (housekeeping_flags & flags)
+			return cpumask_test_cpu(cpu, housekeeping_mask);
 	return true;
 }
 EXPORT_SYMBOL_GPL(housekeeping_test_cpu);
@@ -65,6 +67,8 @@ void __init housekeeping_init(void)
 	cpumask_andnot(housekeeping_mask,
 		       cpu_possible_mask, tick_nohz_full_mask);
 
+	housekeeping_flags = HK_FLAG_TIMER | HK_FLAG_RCU | HK_FLAG_MISC;
+
 	static_branch_enable(&housekeeping_overriden);
 
 	/* We need at least one CPU to handle housekeeping work */
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 562652c..e9e2ebb 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -777,7 +777,8 @@ void __init lockup_detector_init(void)
 	if (tick_nohz_full_enabled())
 		pr_info("Disabling watchdog on nohz_full cores by default\n");
 
-	cpumask_copy(&watchdog_cpumask, housekeeping_cpumask());
+	cpumask_copy(&watchdog_cpumask,
+		     housekeeping_cpumask(HK_FLAG_TIMER));
 
 	if (!watchdog_nmi_probe())
 		nmi_watchdog_available = true;
-- 
2.7.4

  parent reply index

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-27  2:42 [GIT PULL] Housekeeping subsystem v6 Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 01/12] housekeeping: Move housekeeping related code to its own file Frederic Weisbecker
2017-10-27 12:01   ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 02/12] watchdog: Use housekeeping_cpumask() instead of ad-hoc version Frederic Weisbecker
2017-10-27 12:02   ` [tip:sched/core] sched/isolation, " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 03/12] housekeeping: Provide a dynamic off-case to housekeeping_any_cpu() Frederic Weisbecker
2017-10-27 12:02   ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 04/12] housekeeping: Make housekeeping cpumask private Frederic Weisbecker
2017-10-27 12:03   ` [tip:sched/core] sched/isolation: Make the " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 05/12] housekeeping: Use its own static key Frederic Weisbecker
2017-10-27 12:03   ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 06/12] housekeeping: Rename is_housekeeping_cpu to housekeeping_cpu Frederic Weisbecker
2017-10-27 12:03   ` [tip:sched/core] sched/isolation: Rename is_housekeeping_cpu() to housekeeping_cpu() tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 07/12] housekeeping: Move it under its own config, independent from NO_HZ Frederic Weisbecker
2017-10-27 12:04   ` [tip:sched/core] sched/isolation: Split out new CONFIG_CPU_ISOLATION=y config from CONFIG_NO_HZ_FULL tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` Frederic Weisbecker [this message]
2017-10-27 12:04   ` [tip:sched/core] sched/isolation: Introduce housekeeping flags tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 09/12] housekeeping: Handle the nohz_full= parameter Frederic Weisbecker
2017-10-27 12:05   ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 10/12] housekeeping: Move isolcpus to housekeeping Frederic Weisbecker
2017-10-27 12:05   ` [tip:sched/core] sched/isolation: Move isolcpus= handling to the housekeeping code tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 11/12] housekeeping: Add basic isolcpus flags Frederic Weisbecker
2017-10-27 12:05   ` [tip:sched/core] sched/isolation: " tip-bot for Frederic Weisbecker
2017-10-27  2:42 ` [PATCH 12/12] housekeeping: Document " Frederic Weisbecker
2017-10-27 12:06   ` [tip:sched/core] sched/isolation: Document the isolcpus= flags tip-bot for Frederic Weisbecker
2017-10-27 13:58     ` Peter Zijlstra
2017-10-27 14:36       ` Frederic Weisbecker
2017-10-27 17:06         ` Ingo Molnar
2017-10-27 17:33           ` Frederic Weisbecker
2017-10-27 18:21             ` Ingo Molnar
2017-10-27 18:39               ` Frederic Weisbecker
2017-10-27 19:04                 ` Ingo Molnar
2017-10-27 14:38       ` Mike Galbraith
2017-10-30 15:48       ` Christopher Lameter
2017-10-30 16:11         ` Peter Zijlstra
2017-10-30 16:30           ` Christopher Lameter
2017-10-30 16:58             ` Peter Zijlstra
2017-10-30 16:56           ` Mike Galbraith
  -- strict thread matches above, loose matches on Subject: below --
2017-10-24 13:06 [GIT PULL] Introduce housekeeping subsystem v5 Frederic Weisbecker
2017-10-24 13:06 ` [PATCH 08/12] housekeeping: Introduce housekeeping flags Frederic Weisbecker
2017-09-18 13:53 [GIT PULL] Introduce housekeeping subsystem v4 Frederic Weisbecker
2017-09-18 13:54 ` [PATCH 08/12] housekeeping: Introduce housekeeping flags Frederic Weisbecker
2017-09-01 16:41 [PATCH 00/12] Introduce housekeeping subsystem v3 Frederic Weisbecker
2017-09-01 16:41 ` [PATCH 08/12] housekeeping: Introduce housekeeping flags Frederic Weisbecker

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1509072159-31808-9-git-send-email-frederic@kernel.org \
    --to=frederic@kernel.org \
    --cc=cl@linux.com \
    --cc=cmetcalf@mellanox.com \
    --cc=efault@gmx.de \
    --cc=kernellwp@gmail.com \
    --cc=lcapitulino@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=peterz@infradead.org \
    --cc=riel@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git