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authorIngo Molnar <mingo@kernel.org>2016-09-30 08:54:46 (GMT)
committerIngo Molnar <mingo@kernel.org>2016-09-30 08:54:46 (GMT)
commit0b429e18c284af3e7a39f8ec44d95116c473fef8 (patch)
tree7957f57dc70c95a32f71896c9a526ca88b5517ad /kernel
parentd32cdbfb0ba319e44f75437afde868f7cafdc467 (diff)
parent53061afee43bc5041b67a45b6d793e7afdcf9ca7 (diff)
downloadlinux-0b429e18c284af3e7a39f8ec44d95116c473fef8.tar.xz
Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c29
-rw-r--r--kernel/cpuset.c19
-rw-r--r--kernel/events/core.c2
-rw-r--r--kernel/irq/chip.c8
-rw-r--r--kernel/trace/trace.c29
5 files changed, 63 insertions, 24 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index de1c1bd..9ba28310 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3446,9 +3446,28 @@ static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of,
* Except for the root, subtree_control must be zero for a cgroup
* with tasks so that child cgroups don't compete against tasks.
*/
- if (enable && cgroup_parent(cgrp) && !list_empty(&cgrp->cset_links)) {
- ret = -EBUSY;
- goto out_unlock;
+ if (enable && cgroup_parent(cgrp)) {
+ struct cgrp_cset_link *link;
+
+ /*
+ * Because namespaces pin csets too, @cgrp->cset_links
+ * might not be empty even when @cgrp is empty. Walk and
+ * verify each cset.
+ */
+ spin_lock_irq(&css_set_lock);
+
+ ret = 0;
+ list_for_each_entry(link, &cgrp->cset_links, cset_link) {
+ if (css_set_populated(link->cset)) {
+ ret = -EBUSY;
+ break;
+ }
+ }
+
+ spin_unlock_irq(&css_set_lock);
+
+ if (ret)
+ goto out_unlock;
}
/* save and update control masks and prepare csses */
@@ -3899,7 +3918,9 @@ void cgroup_file_notify(struct cgroup_file *cfile)
* cgroup_task_count - count the number of tasks in a cgroup.
* @cgrp: the cgroup in question
*
- * Return the number of tasks in the cgroup.
+ * Return the number of tasks in the cgroup. The returned number can be
+ * higher than the actual number of tasks due to css_set references from
+ * namespace roots and temporary usages.
*/
static int cgroup_task_count(const struct cgroup *cgrp)
{
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index c27e533..2b4c20a 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -325,8 +325,7 @@ static struct file_system_type cpuset_fs_type = {
/*
* Return in pmask the portion of a cpusets's cpus_allowed that
* are online. If none are online, walk up the cpuset hierarchy
- * until we find one that does have some online cpus. The top
- * cpuset always has some cpus online.
+ * until we find one that does have some online cpus.
*
* One way or another, we guarantee to return some non-empty subset
* of cpu_online_mask.
@@ -335,8 +334,20 @@ static struct file_system_type cpuset_fs_type = {
*/
static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask)
{
- while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask))
+ while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask)) {
cs = parent_cs(cs);
+ if (unlikely(!cs)) {
+ /*
+ * The top cpuset doesn't have any online cpu as a
+ * consequence of a race between cpuset_hotplug_work
+ * and cpu hotplug notifier. But we know the top
+ * cpuset's effective_cpus is on its way to to be
+ * identical to cpu_online_mask.
+ */
+ cpumask_copy(pmask, cpu_online_mask);
+ return;
+ }
+ }
cpumask_and(pmask, cs->effective_cpus, cpu_online_mask);
}
@@ -2074,7 +2085,7 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css)
* which could have been changed by cpuset just after it inherits the
* state from the parent and before it sits on the cgroup's task list.
*/
-void cpuset_fork(struct task_struct *task)
+static void cpuset_fork(struct task_struct *task)
{
if (task_css_is_root(task, cpuset_cgrp_id))
return;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index a54f2c2..fc9bb22 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3929,7 +3929,7 @@ static void exclusive_event_destroy(struct perf_event *event)
static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2)
{
- if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) &&
+ if ((e1->pmu == e2->pmu) &&
(e1->cpu == e2->cpu ||
e1->cpu == -1 ||
e2->cpu == -1))
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 6373890..26ba565 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -820,6 +820,8 @@ __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle,
desc->name = name;
if (handle != handle_bad_irq && is_chained) {
+ unsigned int type = irqd_get_trigger_type(&desc->irq_data);
+
/*
* We're about to start this interrupt immediately,
* hence the need to set the trigger configuration.
@@ -828,8 +830,10 @@ __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle,
* chained interrupt. Reset it immediately because we
* do know better.
*/
- __irq_set_trigger(desc, irqd_get_trigger_type(&desc->irq_data));
- desc->handle_irq = handle;
+ if (type != IRQ_TYPE_NONE) {
+ __irq_set_trigger(desc, type);
+ desc->handle_irq = handle;
+ }
irq_settings_set_noprobe(desc);
irq_settings_set_norequest(desc);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index dade4c9..7bc5676 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5124,19 +5124,20 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
struct trace_iterator *iter = filp->private_data;
ssize_t sret;
- /* return any leftover data */
- sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
- if (sret != -EBUSY)
- return sret;
-
- trace_seq_init(&iter->seq);
-
/*
* Avoid more than one consumer on a single file descriptor
* This is just a matter of traces coherency, the ring buffer itself
* is protected.
*/
mutex_lock(&iter->mutex);
+
+ /* return any leftover data */
+ sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
+ if (sret != -EBUSY)
+ goto out;
+
+ trace_seq_init(&iter->seq);
+
if (iter->trace->read) {
sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
if (sret)
@@ -6163,9 +6164,6 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
return -EBUSY;
#endif
- if (splice_grow_spd(pipe, &spd))
- return -ENOMEM;
-
if (*ppos & (PAGE_SIZE - 1))
return -EINVAL;
@@ -6175,6 +6173,9 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
len &= PAGE_MASK;
}
+ if (splice_grow_spd(pipe, &spd))
+ return -ENOMEM;
+
again:
trace_access_lock(iter->cpu_file);
entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
@@ -6232,19 +6233,21 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
/* did we read anything? */
if (!spd.nr_pages) {
if (ret)
- return ret;
+ goto out;
+ ret = -EAGAIN;
if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK))
- return -EAGAIN;
+ goto out;
ret = wait_on_pipe(iter, true);
if (ret)
- return ret;
+ goto out;
goto again;
}
ret = splice_to_pipe(pipe, &spd);
+out:
splice_shrink_spd(&spd);
return ret;