From: tip-bot for Sebastian Andrzej Siewior <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: peterz@infradead.org, hpa@zytor.com,
linux-kernel@vger.kernel.org, tglx@linutronix.de,
mingo@kernel.org, bigeasy@linutronix.de, rostedt@goodmis.org
Subject: [tip:smp/hotplug] stop_machine: Provide stop_machine_cpuslocked()
Date: Thu, 20 Apr 2017 04:19:22 -0700 [thread overview]
Message-ID: <tip-e878ce0f69caa5c37f3183af711291c0c6a38d6a@git.kernel.org> (raw)
In-Reply-To: <20170418170552.526243990@linutronix.de>
Commit-ID: e878ce0f69caa5c37f3183af711291c0c6a38d6a
Gitweb: http://git.kernel.org/tip/e878ce0f69caa5c37f3183af711291c0c6a38d6a
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate: Tue, 18 Apr 2017 19:04:44 +0200
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 20 Apr 2017 13:08:50 +0200
stop_machine: Provide stop_machine_cpuslocked()
Some call sites of stop_machine() are within a get_online_cpus() protected
region.
stop_machine() calls get_online_cpus() as well, which is possible in the
current implementation but prevents converting the hotplug locking to a
percpu rwsem.
Provide stop_machine_cpuslocked() to avoid nested calls to get_online_cpus().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170418170552.526243990@linutronix.de
---
include/linux/stop_machine.h | 26 +++++++++++++++++++++++---
kernel/stop_machine.c | 5 +++--
2 files changed, 26 insertions(+), 5 deletions(-)
diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h
index 3cc9632..8a068bd 100644
--- a/include/linux/stop_machine.h
+++ b/include/linux/stop_machine.h
@@ -116,15 +116,29 @@ static inline int try_stop_cpus(const struct cpumask *cpumask,
* @fn() runs.
*
* This can be thought of as a very heavy write lock, equivalent to
- * grabbing every spinlock in the kernel. */
+ * grabbing every spinlock in the kernel.
+ *
+ * Protects against CPU hotplug.
+ */
int stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus);
+/**
+ * stop_machine_cpuslocked: freeze the machine on all CPUs and run this function
+ * @fn: the function to run
+ * @data: the data ptr for the @fn()
+ * @cpus: the cpus to run the @fn() on (NULL = any online cpu)
+ *
+ * Same as above. Must be called from with in a get_online_cpus() protected
+ * region. Avoids nested calls to get_online_cpus().
+ */
+int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus);
+
int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data,
const struct cpumask *cpus);
#else /* CONFIG_SMP || CONFIG_HOTPLUG_CPU */
-static inline int stop_machine(cpu_stop_fn_t fn, void *data,
- const struct cpumask *cpus)
+static inline int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data,
+ const struct cpumask *cpus)
{
unsigned long flags;
int ret;
@@ -134,6 +148,12 @@ static inline int stop_machine(cpu_stop_fn_t fn, void *data,
return ret;
}
+static inline int stop_machine(cpu_stop_fn_t fn, void *data,
+ const struct cpumask *cpus)
+{
+ return stop_machine_cpuslocked(fn, data, cpus);
+}
+
static inline int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data,
const struct cpumask *cpus)
{
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 1eb8266..a8c5636 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -552,7 +552,8 @@ static int __init cpu_stop_init(void)
}
early_initcall(cpu_stop_init);
-static int __stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus)
+int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data,
+ const struct cpumask *cpus)
{
struct multi_stop_data msdata = {
.fn = fn,
@@ -591,7 +592,7 @@ int stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus)
/* No CPUs can come up or down during this. */
get_online_cpus();
- ret = __stop_machine(fn, data, cpus);
+ ret = stop_machine_cpuslocked(fn, data, cpus);
put_online_cpus();
return ret;
}
next prev parent reply other threads:[~2017-04-20 11:22 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-18 17:04 [patch V2 00/24] cpu/hotplug: Convert get_online_cpus() to a percpu_rwsem Thomas Gleixner
2017-04-18 17:04 ` [patch V2 01/24] cpu/hotplug: Provide cpuhp_setup/remove_state[_nocalls]_cpuslocked() Thomas Gleixner
2017-04-20 11:18 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 02/24] stop_machine: Provide stop_machine_cpuslocked() Thomas Gleixner
2017-04-20 11:19 ` tip-bot for Sebastian Andrzej Siewior [this message]
2017-04-18 17:04 ` [patch V2 03/24] padata: Make padata_alloc() static Thomas Gleixner
2017-04-20 11:19 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:04 ` [patch V2 04/24] padata: Avoid nested calls to get_online_cpus() in pcrypt_init_padata() Thomas Gleixner
2017-04-20 11:20 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 05/24] x86/mtrr: Remove get_online_cpus() from mtrr_save_state() Thomas Gleixner
2017-04-20 11:20 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 06/24] cpufreq: Use cpuhp_setup_state_nocalls_cpuslocked() Thomas Gleixner
2017-04-20 11:21 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 07/24] KVM/PPC/Book3S HV: " Thomas Gleixner
2017-04-20 11:21 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 08/24] hwtracing/coresight-etm3x: " Thomas Gleixner
2017-04-20 11:22 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-20 15:14 ` [patch V2 08/24] " Mathieu Poirier
2017-04-20 15:32 ` Mathieu Poirier
2017-04-18 17:04 ` [patch V2 09/24] hwtracing/coresight-etm4x: " Thomas Gleixner
2017-04-20 11:22 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 10/24] perf/x86/intel/cqm: Use cpuhp_setup_state_cpuslocked() Thomas Gleixner
2017-04-20 11:23 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 11/24] ARM/hw_breakpoint: " Thomas Gleixner
2017-04-19 17:54 ` Mark Rutland
2017-04-19 18:20 ` Thomas Gleixner
2017-04-20 11:23 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 12/24] s390/kernel: Use stop_machine_cpuslocked() Thomas Gleixner
2017-04-20 11:24 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 13/24] powerpc/powernv: " Thomas Gleixner
2017-04-20 11:24 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 14/24] cpu/hotplug: Use stop_machine_cpuslocked() in takedown_cpu() Thomas Gleixner
2017-04-20 11:25 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 15/24] x86/perf: Drop EXPORT of perf_check_microcode Thomas Gleixner
2017-04-20 11:25 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:04 ` [patch V2 16/24] perf/x86/intel: Drop get_online_cpus() in intel_snb_check_microcode() Thomas Gleixner
2017-04-20 11:26 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
2017-04-18 17:04 ` [patch V2 17/24] PCI: Use cpu_hotplug_disable() instead of get_online_cpus() Thomas Gleixner
2017-04-20 11:27 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:05 ` [patch V2 18/24] PCI: Replace the racy recursion prevention Thomas Gleixner
2017-04-20 11:27 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:05 ` [patch V2 19/24] ACPI/processor: Use cpu_hotplug_disable() instead of get_online_cpus() Thomas Gleixner
2017-04-20 11:28 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:05 ` [patch V2 20/24] perf/core: Remove redundant get_online_cpus() Thomas Gleixner
2017-04-20 11:28 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-04-18 17:05 ` [patch V2 21/24] jump_label: Pull get_online_cpus() into generic code Thomas Gleixner
2017-04-18 17:05 ` [patch V2 22/24] jump_label: Provide static_key_slow_inc_cpuslocked() Thomas Gleixner
2017-04-18 17:05 ` [patch V2 23/24] perf: Avoid cpu_hotplug_lock r-r recursion Thomas Gleixner
2017-04-18 17:05 ` [patch V2 24/24] cpu/hotplug: Convert hotplug locking to percpu rwsem Thomas Gleixner
2017-04-20 11:30 ` [tip:smp/hotplug] " tip-bot for Thomas Gleixner
2017-05-10 4:59 ` [patch V2 24/24] " Michael Ellerman
2017-05-10 8:49 ` Thomas Gleixner
2017-05-10 16:30 ` Steven Rostedt
2017-05-10 17:15 ` Steven Rostedt
2017-05-11 5:49 ` Michael Ellerman
2017-04-25 16:10 ` [patch V2 00/24] cpu/hotplug: Convert get_online_cpus() to a percpu_rwsem Mark Rutland
2017-04-25 17:28 ` Sebastian Siewior
2017-04-26 8:59 ` Mark Rutland
2017-04-26 9:40 ` Suzuki K Poulose
2017-04-26 10:32 ` Mark Rutland
2017-04-27 8:27 ` Sebastian Siewior
2017-04-27 9:57 ` Mark Rutland
2017-04-27 10:01 ` Thomas Gleixner
2017-04-27 12:30 ` Mark Rutland
2017-04-27 15:48 ` [PATCH] arm64: cpufeature: use static_branch_enable_cpuslocked() (was: Re: [patch V2 00/24] cpu/hotplug: Convert get_online_cpus() to a percpu_rwsem) Mark Rutland
2017-04-27 16:35 ` Suzuki K Poulose
2017-04-27 17:03 ` [PATCH] arm64: cpufeature: use static_branch_enable_cpuslocked() Suzuki K Poulose
2017-04-27 17:17 ` Mark Rutland
2017-04-28 14:24 ` [RFC PATCH] trace/perf: cure locking issue in perf_event_open() error path Sebastian Siewior
2017-04-28 14:27 ` Sebastian Siewior
2017-05-01 12:57 ` [tip:smp/hotplug] perf: Reorder cpu hotplug rwsem against cred_guard_mutex tip-bot for Thomas Gleixner
2017-05-01 12:58 ` [tip:smp/hotplug] perf: Push hotplug protection down to callers tip-bot for Thomas Gleixner
2017-05-24 8:15 [patch V3 05/32] stop_machine: Provide stop_machine_cpuslocked() Thomas Gleixner
2017-05-26 8:33 ` [tip:smp/hotplug] " tip-bot for Sebastian Andrzej Siewior
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