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-rw-r--r--kernel/sched/cpufreq_schedutil.c49
-rw-r--r--kernel/sched/ext.c50
2 files changed, 49 insertions, 50 deletions
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 1a19d69b91ed..816f07f9d30f 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -81,9 +81,23 @@ static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time)
if (!cpufreq_this_cpu_can_update(sg_policy->policy))
return false;
- if (unlikely(sg_policy->limits_changed)) {
- sg_policy->limits_changed = false;
- sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS);
+ if (unlikely(READ_ONCE(sg_policy->limits_changed))) {
+ WRITE_ONCE(sg_policy->limits_changed, false);
+ sg_policy->need_freq_update = true;
+
+ /*
+ * The above limits_changed update must occur before the reads
+ * of policy limits in cpufreq_driver_resolve_freq() or a policy
+ * limits update might be missed, so use a memory barrier to
+ * ensure it.
+ *
+ * This pairs with the write memory barrier in sugov_limits().
+ */
+ smp_mb();
+
+ return true;
+ } else if (sg_policy->need_freq_update) {
+ /* ignore_dl_rate_limit() wants a new frequency to be found. */
return true;
}
@@ -95,10 +109,22 @@ static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time)
static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time,
unsigned int next_freq)
{
- if (sg_policy->need_freq_update)
+ if (sg_policy->need_freq_update) {
sg_policy->need_freq_update = false;
- else if (sg_policy->next_freq == next_freq)
+ /*
+ * The policy limits have changed, but if the return value of
+ * cpufreq_driver_resolve_freq() after applying the new limits
+ * is still equal to the previously selected frequency, the
+ * driver callback need not be invoked unless the driver
+ * specifically wants that to happen on every update of the
+ * policy limits.
+ */
+ if (sg_policy->next_freq == next_freq &&
+ !cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS))
+ return false;
+ } else if (sg_policy->next_freq == next_freq) {
return false;
+ }
sg_policy->next_freq = next_freq;
sg_policy->last_freq_update_time = time;
@@ -365,7 +391,7 @@ static inline bool sugov_hold_freq(struct sugov_cpu *sg_cpu) { return false; }
static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu)
{
if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_min)
- sg_cpu->sg_policy->limits_changed = true;
+ sg_cpu->sg_policy->need_freq_update = true;
}
static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu,
@@ -871,7 +897,16 @@ static void sugov_limits(struct cpufreq_policy *policy)
mutex_unlock(&sg_policy->work_lock);
}
- sg_policy->limits_changed = true;
+ /*
+ * The limits_changed update below must take place before the updates
+ * of policy limits in cpufreq_set_policy() or a policy limits update
+ * might be missed, so use a memory barrier to ensure it.
+ *
+ * This pairs with the memory barrier in sugov_should_update_freq().
+ */
+ smp_wmb();
+
+ WRITE_ONCE(sg_policy->limits_changed, true);
}
struct cpufreq_governor schedutil_gov = {
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 66bcd40a28ca..fdbf249d1c68 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -163,7 +163,7 @@ enum scx_ops_flags {
/*
* CPU cgroup support flags
*/
- SCX_OPS_HAS_CGROUP_WEIGHT = 1LLU << 16, /* cpu.weight */
+ SCX_OPS_HAS_CGROUP_WEIGHT = 1LLU << 16, /* DEPRECATED, will be removed on 6.18 */
SCX_OPS_ALL_FLAGS = SCX_OPS_KEEP_BUILTIN_IDLE |
SCX_OPS_ENQ_LAST |
@@ -3899,35 +3899,6 @@ bool scx_can_stop_tick(struct rq *rq)
DEFINE_STATIC_PERCPU_RWSEM(scx_cgroup_rwsem);
static bool scx_cgroup_enabled;
-static bool cgroup_warned_missing_weight;
-static bool cgroup_warned_missing_idle;
-
-static void scx_cgroup_warn_missing_weight(struct task_group *tg)
-{
- if (scx_ops_enable_state() == SCX_OPS_DISABLED ||
- cgroup_warned_missing_weight)
- return;
-
- if ((scx_ops.flags & SCX_OPS_HAS_CGROUP_WEIGHT) || !tg->css.parent)
- return;
-
- pr_warn("sched_ext: \"%s\" does not implement cgroup cpu.weight\n",
- scx_ops.name);
- cgroup_warned_missing_weight = true;
-}
-
-static void scx_cgroup_warn_missing_idle(struct task_group *tg)
-{
- if (!scx_cgroup_enabled || cgroup_warned_missing_idle)
- return;
-
- if (!tg->idle)
- return;
-
- pr_warn("sched_ext: \"%s\" does not implement cgroup cpu.idle\n",
- scx_ops.name);
- cgroup_warned_missing_idle = true;
-}
int scx_tg_online(struct task_group *tg)
{
@@ -3937,8 +3908,6 @@ int scx_tg_online(struct task_group *tg)
percpu_down_read(&scx_cgroup_rwsem);
- scx_cgroup_warn_missing_weight(tg);
-
if (scx_cgroup_enabled) {
if (SCX_HAS_OP(cgroup_init)) {
struct scx_cgroup_init_args args =
@@ -4076,9 +4045,7 @@ void scx_group_set_weight(struct task_group *tg, unsigned long weight)
void scx_group_set_idle(struct task_group *tg, bool idle)
{
- percpu_down_read(&scx_cgroup_rwsem);
- scx_cgroup_warn_missing_idle(tg);
- percpu_up_read(&scx_cgroup_rwsem);
+ /* TODO: Implement ops->cgroup_set_idle() */
}
static void scx_cgroup_lock(void)
@@ -4272,9 +4239,6 @@ static int scx_cgroup_init(void)
percpu_rwsem_assert_held(&scx_cgroup_rwsem);
- cgroup_warned_missing_weight = false;
- cgroup_warned_missing_idle = false;
-
/*
* scx_tg_on/offline() are excluded through scx_cgroup_rwsem. If we walk
* cgroups and init, all online cgroups are initialized.
@@ -4284,9 +4248,6 @@ static int scx_cgroup_init(void)
struct task_group *tg = css_tg(css);
struct scx_cgroup_init_args args = { .weight = tg->scx_weight };
- scx_cgroup_warn_missing_weight(tg);
- scx_cgroup_warn_missing_idle(tg);
-
if ((tg->scx_flags &
(SCX_TG_ONLINE | SCX_TG_INITED)) != SCX_TG_ONLINE)
continue;
@@ -4623,7 +4584,7 @@ unlock:
static void free_exit_info(struct scx_exit_info *ei)
{
- kfree(ei->dump);
+ kvfree(ei->dump);
kfree(ei->msg);
kfree(ei->bt);
kfree(ei);
@@ -4639,7 +4600,7 @@ static struct scx_exit_info *alloc_exit_info(size_t exit_dump_len)
ei->bt = kcalloc(SCX_EXIT_BT_LEN, sizeof(ei->bt[0]), GFP_KERNEL);
ei->msg = kzalloc(SCX_EXIT_MSG_LEN, GFP_KERNEL);
- ei->dump = kzalloc(exit_dump_len, GFP_KERNEL);
+ ei->dump = kvzalloc(exit_dump_len, GFP_KERNEL);
if (!ei->bt || !ei->msg || !ei->dump) {
free_exit_info(ei);
@@ -5252,6 +5213,9 @@ static int validate_ops(const struct sched_ext_ops *ops)
return -EINVAL;
}
+ if (ops->flags & SCX_OPS_HAS_CGROUP_WEIGHT)
+ pr_warn("SCX_OPS_HAS_CGROUP_WEIGHT is deprecated and a noop\n");
+
return 0;
}
generated by cgit v1.2.3 (git 2.46.0) at 2025-04-25 19:46:58 +0000