Files
omarchy-pkgs/pkgbuilds/linux-omarchy-bore/0141-sched-urgent-fixes.patch
T

126 lines
4.0 KiB
Diff

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -3026,8 +3026,8 @@ static struct task_struct *pick_next_pushable_dl_task(struct rq *rq)
next_node = rb_first_cached(&rq->dl.pushable_dl_tasks_root);
while (next_node) {
i = __node_2_pdl(next_node);
- /* make sure task isn't on_cpu (possible with proxy-exec) */
- if (!task_on_cpu(rq, i)) {
+ /* skip tasks that cannot be migrated */
+ if (!task_on_cpu(rq, i) && !is_migration_disabled(i)) {
p = i;
break;
}
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -10691,17 +10691,40 @@ static enum llc_mig can_migrate_llc(int src_cpu, int dst_cpu,
return mig_llc;
}
+static inline bool task_misfits_asym_cpu(struct lb_env *env, struct task_struct *p)
+{
+ /*
+ * On asymmetric CPU capacity domains, do not let cache-aware
+ * balancing pull the task onto a destination CPU that cannot
+ * accommodate it. Doing so would turn the task into a misfit on
+ * the destination, trading a cache-locality gain for a capacity
+ * loss. If the task already does not fit its source CPU, the move
+ * cannot make things worse, so let the LLC preference decide.
+ */
+ if ((env->sd->flags & SD_ASYM_CPUCAPACITY) && p &&
+ !task_fits_cpu(p, env->dst_cpu) &&
+ task_fits_cpu(p, env->src_cpu))
+ return true;
+
+ return false;
+}
+
/*
* Check if task p can migrate from source LLC to
* destination LLC in terms of cache aware load balance.
*/
-static enum llc_mig can_migrate_llc_task(int src_cpu, int dst_cpu,
+static enum llc_mig can_migrate_llc_task(struct lb_env *env,
struct task_struct *p)
{
struct mm_struct *mm;
bool to_pref;
- int cpu;
+ int cpu, src_cpu, dst_cpu;
+ if (task_misfits_asym_cpu(env, p))
+ return mig_forbid;
+
+ src_cpu = env->src_cpu;
+ dst_cpu = env->dst_cpu;
mm = p->mm;
if (!mm)
return mig_unrestricted;
@@ -10758,6 +10781,14 @@ alb_break_llc(struct lb_env *env)
unsigned long util = 0;
struct task_struct *cur;
+ /*
+ * Migrating misfit tasks from current CPU
+ * to CPU with a better fit.
+ * Prioritize that over LLC preference.
+ */
+ if (env->migration_type == migrate_misfit)
+ return false;
+
if (env->src_rq->nr_running <= 1)
return true;
@@ -10765,7 +10796,8 @@ alb_break_llc(struct lb_env *env)
if (cur && cur->sched_class == &fair_sched_class)
util = task_util(cur);
- if (can_migrate_llc(env->src_cpu, env->dst_cpu,
+ if (task_misfits_asym_cpu(env, cur) ||
+ can_migrate_llc(env->src_cpu, env->dst_cpu,
util, false) == mig_forbid)
return true;
}
@@ -10805,8 +10837,7 @@ static bool migrate_degrades_llc(struct task_struct *p, struct lb_env *env)
READ_ONCE(p->preferred_llc) != llc_id(env->dst_cpu))
return true;
- if (can_migrate_llc_task(env->src_cpu,
- env->dst_cpu, p) != mig_forbid)
+ if (can_migrate_llc_task(env, p) != mig_forbid)
return false;
return true;
@@ -11869,6 +11900,15 @@ static inline bool llc_balance(struct lb_env *env, struct sg_lb_stats *sgs,
if (env->sd->flags & SD_SHARE_LLC)
return false;
+ /*
+ * On asymmetric domains, group_misfit_task_load
+ * should be prioritized to move tasks to CPU that fit them
+ * over aggregating tasks to their preferred LLC.
+ */
+ if ((env->sd->flags & SD_ASYM_CPUCAPACITY) &&
+ sgs->group_misfit_task_load)
+ return false;
+
/*
* Skip cache aware tagging if nr_balanced_failed is sufficiently high.
* Threshold of cache_nice_tries is set to 1 higher than nr_balance_failed
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1871,8 +1871,8 @@ static struct task_struct *pick_next_pushable_task(struct rq *rq)
return NULL;
plist_for_each_entry(i, head, pushable_tasks) {
- /* make sure task isn't on_cpu (possible with proxy-exec) */
- if (!task_on_cpu(rq, i)) {
+ /* skip tasks that cannot be migrated */
+ if (!task_on_cpu(rq, i) && !is_migration_disabled(i)) {
p = i;
break;
}