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-rw-r--r--debian/patches-rt/0256-cpuset-Convert-callback_lock-to-raw_spinlock_t.patch293
1 files changed, 293 insertions, 0 deletions
diff --git a/debian/patches-rt/0256-cpuset-Convert-callback_lock-to-raw_spinlock_t.patch b/debian/patches-rt/0256-cpuset-Convert-callback_lock-to-raw_spinlock_t.patch
new file mode 100644
index 000000000..68ac442a9
--- /dev/null
+++ b/debian/patches-rt/0256-cpuset-Convert-callback_lock-to-raw_spinlock_t.patch
@@ -0,0 +1,293 @@
+From fd27c495e357db5ecab593fc59617b9c3f39c770 Mon Sep 17 00:00:00 2001
+From: Mike Galbraith <efault@gmx.de>
+Date: Sun, 8 Jan 2017 09:32:25 +0100
+Subject: [PATCH 256/347] cpuset: Convert callback_lock to raw_spinlock_t
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz
+
+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/cgroup/cpuset.c | 66 +++++++++++++++++++++---------------------
+ 1 file changed, 33 insertions(+), 33 deletions(-)
+
+diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
+index 35541e1dfad9..42ed4e497336 100644
+--- a/kernel/cgroup/cpuset.c
++++ b/kernel/cgroup/cpuset.c
+@@ -288,7 +288,7 @@ 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;
+
+@@ -922,9 +922,9 @@ 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(!is_in_v2_mode() &&
+ !cpumask_equal(cp->cpus_allowed, cp->effective_cpus));
+@@ -989,9 +989,9 @@ 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);
+- 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);
+@@ -1175,9 +1175,9 @@ 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(!is_in_v2_mode() &&
+ !nodes_equal(cp->mems_allowed, cp->effective_mems));
+@@ -1245,9 +1245,9 @@ 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);
+@@ -1338,9 +1338,9 @@ 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();
+@@ -1761,7 +1761,7 @@ 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:
+@@ -1780,7 +1780,7 @@ 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;
+ }
+
+@@ -1995,12 +1995,12 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
+
+ cpuset_inc();
+
+- spin_lock_irq(&callback_lock);
++ raw_spin_lock_irq(&callback_lock);
+ if (is_in_v2_mode()) {
+ 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;
+@@ -2027,12 +2027,12 @@ 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->effective_cpus, parent->cpus_allowed);
+- spin_unlock_irq(&callback_lock);
++ raw_spin_unlock_irq(&callback_lock);
+ out_unlock:
+ mutex_unlock(&cpuset_mutex);
+ return 0;
+@@ -2071,7 +2071,7 @@ 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 (is_in_v2_mode()) {
+ cpumask_copy(top_cpuset.cpus_allowed, cpu_possible_mask);
+@@ -2082,7 +2082,7 @@ 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);
+ }
+
+@@ -2180,12 +2180,12 @@ 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,
+@@ -2222,10 +2222,10 @@ 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);
+@@ -2318,21 +2318,21 @@ 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);
+ }
+
+@@ -2434,11 +2434,11 @@ 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);
+ }
+
+ /**
+@@ -2499,11 +2499,11 @@ 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;
+ }
+@@ -2595,14 +2595,14 @@ 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;
+ }
+
+--
+2.36.1
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-28 17:48:00 +0000