forked from rrcarlosr/Jetpack
295 lines
9.8 KiB
Diff
295 lines
9.8 KiB
Diff
From 8e13b3aaec43953cf0c90eb8f26bff153b9e0d3e Mon Sep 17 00:00:00 2001
|
|
From: Mike Galbraith <efault@gmx.de>
|
|
Date: Sun, 8 Jan 2017 09:32:25 +0100
|
|
Subject: [PATCH 322/352] cpuset: Convert callback_lock to raw_spinlock_t
|
|
|
|
The two commits below add up to a cpuset might_sleep() splat for RT:
|
|
|
|
8447a0fee974 cpuset: convert callback_mutex to a spinlock
|
|
344736f29b35 cpuset: simplify cpuset_node_allowed API
|
|
|
|
BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:995
|
|
in_atomic(): 0, irqs_disabled(): 1, pid: 11718, name: cset
|
|
CPU: 135 PID: 11718 Comm: cset Tainted: G E 4.10.0-rt1-rt #4
|
|
Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BRHSXSD1.86B.0056.R01.1409242327 09/24/2014
|
|
Call Trace:
|
|
? dump_stack+0x5c/0x81
|
|
? ___might_sleep+0xf4/0x170
|
|
? rt_spin_lock+0x1c/0x50
|
|
? __cpuset_node_allowed+0x66/0xc0
|
|
? ___slab_alloc+0x390/0x570 <disables IRQs>
|
|
? anon_vma_fork+0x8f/0x140
|
|
? copy_page_range+0x6cf/0xb00
|
|
? anon_vma_fork+0x8f/0x140
|
|
? __slab_alloc.isra.74+0x5a/0x81
|
|
? anon_vma_fork+0x8f/0x140
|
|
? kmem_cache_alloc+0x1b5/0x1f0
|
|
? anon_vma_fork+0x8f/0x140
|
|
? copy_process.part.35+0x1670/0x1ee0
|
|
? _do_fork+0xdd/0x3f0
|
|
? _do_fork+0xdd/0x3f0
|
|
? do_syscall_64+0x61/0x170
|
|
? entry_SYSCALL64_slow_path+0x25/0x25
|
|
|
|
The later ensured that a NUMA box WILL take callback_lock in atomic
|
|
context by removing the allocator and reclaim path __GFP_HARDWALL
|
|
usage which prevented such contexts from taking callback_mutex.
|
|
|
|
One option would be to reinstate __GFP_HARDWALL protections for
|
|
RT, however, as the 8447a0fee974 changelog states:
|
|
|
|
The callback_mutex is only used to synchronize reads/updates of cpusets'
|
|
flags and cpu/node masks. These operations should always proceed fast so
|
|
there's no reason why we can't use a spinlock instead of the mutex.
|
|
|
|
Cc: stable-rt@vger.kernel.org
|
|
Signed-off-by: Mike Galbraith <efault@gmx.de>
|
|
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
---
|
|
kernel/cpuset.c | 66 ++++++++++++++++++++++++++++-----------------------------
|
|
1 file changed, 33 insertions(+), 33 deletions(-)
|
|
|
|
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
|
|
index 435d500..934329e 100644
|
|
--- a/kernel/cpuset.c
|
|
+++ b/kernel/cpuset.c
|
|
@@ -286,7 +286,7 @@ static struct cpuset top_cpuset = {
|
|
*/
|
|
|
|
static DEFINE_MUTEX(cpuset_mutex);
|
|
-static DEFINE_SPINLOCK(callback_lock);
|
|
+static DEFINE_RAW_SPINLOCK(callback_lock);
|
|
|
|
static struct workqueue_struct *cpuset_migrate_mm_wq;
|
|
|
|
@@ -917,9 +917,9 @@ static void update_cpumasks_hier(struct cpuset *cs, struct cpumask *new_cpus)
|
|
continue;
|
|
rcu_read_unlock();
|
|
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
cpumask_copy(cp->effective_cpus, new_cpus);
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
|
|
WARN_ON(!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
|
|
!cpumask_equal(cp->cpus_allowed, cp->effective_cpus));
|
|
@@ -985,10 +985,10 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
|
|
if (retval < 0)
|
|
return retval;
|
|
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed);
|
|
cpumask_copy(cs->cpus_requested, trialcs->cpus_requested);
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
|
|
/* use trialcs->cpus_allowed as a temp variable */
|
|
update_cpumasks_hier(cs, trialcs->cpus_allowed);
|
|
@@ -1188,9 +1188,9 @@ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems)
|
|
continue;
|
|
rcu_read_unlock();
|
|
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
cp->effective_mems = *new_mems;
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
|
|
WARN_ON(!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) &&
|
|
!nodes_equal(cp->mems_allowed, cp->effective_mems));
|
|
@@ -1258,9 +1258,9 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,
|
|
if (retval < 0)
|
|
goto done;
|
|
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
cs->mems_allowed = trialcs->mems_allowed;
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
|
|
/* use trialcs->mems_allowed as a temp variable */
|
|
update_nodemasks_hier(cs, &trialcs->mems_allowed);
|
|
@@ -1351,9 +1351,9 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
|
|
spread_flag_changed = ((is_spread_slab(cs) != is_spread_slab(trialcs))
|
|
|| (is_spread_page(cs) != is_spread_page(trialcs)));
|
|
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
cs->flags = trialcs->flags;
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
|
|
if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed)
|
|
rebuild_sched_domains_locked();
|
|
@@ -1774,7 +1774,7 @@ static int cpuset_common_seq_show(struct seq_file *sf, void *v)
|
|
cpuset_filetype_t type = seq_cft(sf)->private;
|
|
int ret = 0;
|
|
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
|
|
switch (type) {
|
|
case FILE_CPULIST:
|
|
@@ -1793,7 +1793,7 @@ static int cpuset_common_seq_show(struct seq_file *sf, void *v)
|
|
ret = -EINVAL;
|
|
}
|
|
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
return ret;
|
|
}
|
|
|
|
@@ -2013,12 +2013,12 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
|
|
|
|
cpuset_inc();
|
|
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys)) {
|
|
cpumask_copy(cs->effective_cpus, parent->effective_cpus);
|
|
cs->effective_mems = parent->effective_mems;
|
|
}
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
|
|
if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags))
|
|
goto out_unlock;
|
|
@@ -2045,13 +2045,13 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
cs->mems_allowed = parent->mems_allowed;
|
|
cs->effective_mems = parent->mems_allowed;
|
|
cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
|
|
cpumask_copy(cs->cpus_requested, parent->cpus_requested);
|
|
cpumask_copy(cs->effective_cpus, parent->cpus_allowed);
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
out_unlock:
|
|
mutex_unlock(&cpuset_mutex);
|
|
return 0;
|
|
@@ -2091,7 +2091,7 @@ static void cpuset_css_free(struct cgroup_subsys_state *css)
|
|
static void cpuset_bind(struct cgroup_subsys_state *root_css)
|
|
{
|
|
mutex_lock(&cpuset_mutex);
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
|
|
if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys)) {
|
|
cpumask_copy(top_cpuset.cpus_allowed, cpu_possible_mask);
|
|
@@ -2102,7 +2102,7 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css)
|
|
top_cpuset.mems_allowed = top_cpuset.effective_mems;
|
|
}
|
|
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
mutex_unlock(&cpuset_mutex);
|
|
}
|
|
|
|
@@ -2206,12 +2206,12 @@ hotplug_update_tasks_legacy(struct cpuset *cs,
|
|
{
|
|
bool is_empty;
|
|
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
cpumask_copy(cs->cpus_allowed, new_cpus);
|
|
cpumask_copy(cs->effective_cpus, new_cpus);
|
|
cs->mems_allowed = *new_mems;
|
|
cs->effective_mems = *new_mems;
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
|
|
/*
|
|
* Don't call update_tasks_cpumask() if the cpuset becomes empty,
|
|
@@ -2248,10 +2248,10 @@ hotplug_update_tasks(struct cpuset *cs,
|
|
if (nodes_empty(*new_mems))
|
|
*new_mems = parent_cs(cs)->effective_mems;
|
|
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
cpumask_copy(cs->effective_cpus, new_cpus);
|
|
cs->effective_mems = *new_mems;
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
|
|
if (cpus_updated)
|
|
update_tasks_cpumask(cs);
|
|
@@ -2344,21 +2344,21 @@ static void cpuset_hotplug_workfn(struct work_struct *work)
|
|
|
|
/* synchronize cpus_allowed to cpu_active_mask */
|
|
if (cpus_updated) {
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
if (!on_dfl)
|
|
cpumask_copy(top_cpuset.cpus_allowed, &new_cpus);
|
|
cpumask_copy(top_cpuset.effective_cpus, &new_cpus);
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
/* we don't mess with cpumasks of tasks in top_cpuset */
|
|
}
|
|
|
|
/* synchronize mems_allowed to N_MEMORY */
|
|
if (mems_updated) {
|
|
- spin_lock_irq(&callback_lock);
|
|
+ raw_spin_lock_irq(&callback_lock);
|
|
if (!on_dfl)
|
|
top_cpuset.mems_allowed = new_mems;
|
|
top_cpuset.effective_mems = new_mems;
|
|
- spin_unlock_irq(&callback_lock);
|
|
+ raw_spin_unlock_irq(&callback_lock);
|
|
update_tasks_nodemask(&top_cpuset);
|
|
}
|
|
|
|
@@ -2463,11 +2463,11 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
|
|
{
|
|
unsigned long flags;
|
|
|
|
- spin_lock_irqsave(&callback_lock, flags);
|
|
+ raw_spin_lock_irqsave(&callback_lock, flags);
|
|
rcu_read_lock();
|
|
guarantee_online_cpus(task_cs(tsk), pmask);
|
|
rcu_read_unlock();
|
|
- spin_unlock_irqrestore(&callback_lock, flags);
|
|
+ raw_spin_unlock_irqrestore(&callback_lock, flags);
|
|
}
|
|
|
|
void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
|
|
@@ -2515,11 +2515,11 @@ nodemask_t cpuset_mems_allowed(struct task_struct *tsk)
|
|
nodemask_t mask;
|
|
unsigned long flags;
|
|
|
|
- spin_lock_irqsave(&callback_lock, flags);
|
|
+ raw_spin_lock_irqsave(&callback_lock, flags);
|
|
rcu_read_lock();
|
|
guarantee_online_mems(task_cs(tsk), &mask);
|
|
rcu_read_unlock();
|
|
- spin_unlock_irqrestore(&callback_lock, flags);
|
|
+ raw_spin_unlock_irqrestore(&callback_lock, flags);
|
|
|
|
return mask;
|
|
}
|
|
@@ -2611,14 +2611,14 @@ bool __cpuset_node_allowed(int node, gfp_t gfp_mask)
|
|
return true;
|
|
|
|
/* Not hardwall and node outside mems_allowed: scan up cpusets */
|
|
- spin_lock_irqsave(&callback_lock, flags);
|
|
+ raw_spin_lock_irqsave(&callback_lock, flags);
|
|
|
|
rcu_read_lock();
|
|
cs = nearest_hardwall_ancestor(task_cs(current));
|
|
allowed = node_isset(node, cs->mems_allowed);
|
|
rcu_read_unlock();
|
|
|
|
- spin_unlock_irqrestore(&callback_lock, flags);
|
|
+ raw_spin_unlock_irqrestore(&callback_lock, flags);
|
|
return allowed;
|
|
}
|
|
|
|
--
|
|
2.7.4
|
|
|