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Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup/cpuset.c38
-rw-r--r--kernel/panic.c8
-rw-r--r--kernel/printk/printk.c2
-rw-r--r--kernel/workqueue.c50
4 files changed, 56 insertions, 42 deletions
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 40ec4abaf440..4bd9e50bcc8e 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -233,6 +233,13 @@ static cpumask_var_t isolated_cpus;
static struct list_head remote_children;
/*
+ * A flag to force sched domain rebuild at the end of an operation while
+ * inhibiting it in the intermediate stages when set. Currently it is only
+ * set in hotplug code.
+ */
+static bool force_sd_rebuild;
+
+/*
* Partition root states:
*
* 0 - member (not a partition root)
@@ -1475,7 +1482,7 @@ static void update_partition_sd_lb(struct cpuset *cs, int old_prs)
clear_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
}
- if (rebuild_domains)
+ if (rebuild_domains && !force_sd_rebuild)
rebuild_sched_domains_locked();
}
@@ -1833,7 +1840,7 @@ static void remote_partition_check(struct cpuset *cs, struct cpumask *newmask,
remote_partition_disable(child, tmp);
disable_cnt++;
}
- if (disable_cnt)
+ if (disable_cnt && !force_sd_rebuild)
rebuild_sched_domains_locked();
}
@@ -1991,6 +1998,8 @@ static int update_parent_effective_cpumask(struct cpuset *cs, int cmd,
part_error = PERR_CPUSEMPTY;
goto write_error;
}
+ /* Check newmask again, whether cpus are available for parent/cs */
+ nocpu |= tasks_nocpu_error(parent, cs, newmask);
/*
* partcmd_update with newmask:
@@ -2440,7 +2449,8 @@ get_css:
}
rcu_read_unlock();
- if (need_rebuild_sched_domains && !(flags & HIER_NO_SD_REBUILD))
+ if (need_rebuild_sched_domains && !(flags & HIER_NO_SD_REBUILD) &&
+ !force_sd_rebuild)
rebuild_sched_domains_locked();
}
@@ -2523,7 +2533,8 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
*/
if (!*buf) {
cpumask_clear(trialcs->cpus_allowed);
- cpumask_clear(trialcs->effective_xcpus);
+ if (cpumask_empty(trialcs->exclusive_cpus))
+ cpumask_clear(trialcs->effective_xcpus);
} else {
retval = cpulist_parse(buf, trialcs->cpus_allowed);
if (retval < 0)
@@ -3101,7 +3112,8 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs,
cs->flags = trialcs->flags;
spin_unlock_irq(&callback_lock);
- if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed)
+ if (!cpumask_empty(trialcs->cpus_allowed) && balance_flag_changed &&
+ !force_sd_rebuild)
rebuild_sched_domains_locked();
if (spread_flag_changed)
@@ -4498,11 +4510,9 @@ hotplug_update_tasks(struct cpuset *cs,
update_tasks_nodemask(cs);
}
-static bool force_rebuild;
-
void cpuset_force_rebuild(void)
{
- force_rebuild = true;
+ force_sd_rebuild = true;
}
/**
@@ -4650,15 +4660,9 @@ static void cpuset_handle_hotplug(void)
!cpumask_empty(subpartitions_cpus);
mems_updated = !nodes_equal(top_cpuset.effective_mems, new_mems);
- /*
- * In the rare case that hotplug removes all the cpus in
- * subpartitions_cpus, we assumed that cpus are updated.
- */
- if (!cpus_updated && !cpumask_empty(subpartitions_cpus))
- cpus_updated = true;
-
/* For v1, synchronize cpus_allowed to cpu_active_mask */
if (cpus_updated) {
+ cpuset_force_rebuild();
spin_lock_irq(&callback_lock);
if (!on_dfl)
cpumask_copy(top_cpuset.cpus_allowed, &new_cpus);
@@ -4714,8 +4718,8 @@ static void cpuset_handle_hotplug(void)
}
/* rebuild sched domains if cpus_allowed has changed */
- if (cpus_updated || force_rebuild) {
- force_rebuild = false;
+ if (force_sd_rebuild) {
+ force_sd_rebuild = false;
rebuild_sched_domains_cpuslocked();
}
diff --git a/kernel/panic.c b/kernel/panic.c
index f861bedc1925..2a0449144f82 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -64,6 +64,8 @@ unsigned long panic_on_taint;
bool panic_on_taint_nousertaint = false;
static unsigned int warn_limit __read_mostly;
+bool panic_triggering_all_cpu_backtrace;
+
int panic_timeout = CONFIG_PANIC_TIMEOUT;
EXPORT_SYMBOL_GPL(panic_timeout);
@@ -253,8 +255,12 @@ void check_panic_on_warn(const char *origin)
*/
static void panic_other_cpus_shutdown(bool crash_kexec)
{
- if (panic_print & PANIC_PRINT_ALL_CPU_BT)
+ if (panic_print & PANIC_PRINT_ALL_CPU_BT) {
+ /* Temporary allow non-panic CPUs to write their backtraces. */
+ panic_triggering_all_cpu_backtrace = true;
trigger_all_cpu_backtrace();
+ panic_triggering_all_cpu_backtrace = false;
+ }
/*
* Note that smp_send_stop() is the usual SMP shutdown function,
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 054c0e7784fd..c22b07049c38 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2316,7 +2316,7 @@ asmlinkage int vprintk_emit(int facility, int level,
* non-panic CPUs are generating any messages, they will be
* silently dropped.
*/
- if (other_cpu_in_panic())
+ if (other_cpu_in_panic() && !panic_triggering_all_cpu_backtrace)
return 0;
if (level == LOGLEVEL_SCHED) {
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 1745ca788ede..e7b005ff3750 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -377,7 +377,7 @@ struct workqueue_struct {
/* hot fields used during command issue, aligned to cacheline */
unsigned int flags ____cacheline_aligned; /* WQ: WQ_* flags */
- struct pool_workqueue __percpu __rcu **cpu_pwq; /* I: per-cpu pwqs */
+ struct pool_workqueue __rcu * __percpu *cpu_pwq; /* I: per-cpu pwqs */
struct wq_node_nr_active *node_nr_active[]; /* I: per-node nr_active */
};
@@ -897,7 +897,7 @@ static struct worker_pool *get_work_pool(struct work_struct *work)
static unsigned long shift_and_mask(unsigned long v, u32 shift, u32 bits)
{
- return (v >> shift) & ((1 << bits) - 1);
+ return (v >> shift) & ((1U << bits) - 1);
}
static void work_offqd_unpack(struct work_offq_data *offqd, unsigned long data)
@@ -3351,7 +3351,6 @@ woke_up:
set_pf_worker(false);
ida_free(&pool->worker_ida, worker->id);
- WARN_ON_ONCE(!list_empty(&worker->entry));
return 0;
}
@@ -4167,7 +4166,6 @@ already_gone:
static bool __flush_work(struct work_struct *work, bool from_cancel)
{
struct wq_barrier barr;
- unsigned long data;
if (WARN_ON(!wq_online))
return false;
@@ -4185,29 +4183,35 @@ static bool __flush_work(struct work_struct *work, bool from_cancel)
* was queued on a BH workqueue, we also know that it was running in the
* BH context and thus can be busy-waited.
*/
- data = *work_data_bits(work);
- if (from_cancel &&
- !WARN_ON_ONCE(data & WORK_STRUCT_PWQ) && (data & WORK_OFFQ_BH)) {
- /*
- * On RT, prevent a live lock when %current preempted soft
- * interrupt processing or prevents ksoftirqd from running by
- * keeping flipping BH. If the BH work item runs on a different
- * CPU then this has no effect other than doing the BH
- * disable/enable dance for nothing. This is copied from
- * kernel/softirq.c::tasklet_unlock_spin_wait().
- */
- while (!try_wait_for_completion(&barr.done)) {
- if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
- local_bh_disable();
- local_bh_enable();
- } else {
- cpu_relax();
+ if (from_cancel) {
+ unsigned long data = *work_data_bits(work);
+
+ if (!WARN_ON_ONCE(data & WORK_STRUCT_PWQ) &&
+ (data & WORK_OFFQ_BH)) {
+ /*
+ * On RT, prevent a live lock when %current preempted
+ * soft interrupt processing or prevents ksoftirqd from
+ * running by keeping flipping BH. If the BH work item
+ * runs on a different CPU then this has no effect other
+ * than doing the BH disable/enable dance for nothing.
+ * This is copied from
+ * kernel/softirq.c::tasklet_unlock_spin_wait().
+ */
+ while (!try_wait_for_completion(&barr.done)) {
+ if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+ local_bh_disable();
+ local_bh_enable();
+ } else {
+ cpu_relax();
+ }
}
+ goto out_destroy;
}
- } else {
- wait_for_completion(&barr.done);
}
+ wait_for_completion(&barr.done);
+
+out_destroy:
destroy_work_on_stack(&barr.work);
return true;
}
generated by cgit v1.2.3-70-g09d2 (git 2.47.1) at 2024-12-25 21:16:08 +0000