From 0d6526f82c3cdefcca47f73f5fc08dc6f335eac6 Mon Sep 17 00:00:00 2001 From: Tim Chen Date: Mon, 21 Sep 2026 17:37:22 -0700 Subject: sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling bug alb_break_llc() decides whether to break LLC preference during active load balance. It does so by testing that every runnable fair task on the source rq prefers its LLC: env->src_rq->nr_pref_llc_running == env->src_rq->cfs.h_nr_runnable But the two counters cover different sets. nr_pref_llc_running is updated in account_llc_enqueue()/account_llc_dequeue(), next to cfs_rq->nr_queued, so it follows queued tasks. h_nr_runnable is updated in set_delayed()/ clear_delayed() and drops delay-dequeued tasks. So under DELAY_DEQUEUE, a preferring task that goes to sleep stays counted in nr_pref_llc_running while h_nr_runnable falls. The equality then breaks, alb_break_llc() returns false, and active balance is free to pull a task off its preferred LLC. Active balance only moves runnable tasks, and this is the only LLC check it consults: once the stopper runs, LBF_ACTIVE_LB skips the per-task test in can_migrate_task(). The runnable set is the one we want. Fix it on the counter side. A task should be counted in nr_pref_llc_running exactly while it is both queued on its preferred LLC (pref_llc_queued) and runnable (!sched_delayed). Define that membership once in task_pref_llc_runnable(), and adjust the counter only through pref_llc_running_inc()/pref_llc_running_dec() from the four sites that change either input: account_llc_enqueue(), account_llc_dequeue(), set_delayed() and clear_delayed(). Gating every update on the same predicate keeps the delay, wake and dequeue paths from double-counting or underflowing; see the comments at those sites for the ordering. nr_llc_running and sd->llc_counts are not touched and stay on queued semantics. Fixes: 714059f79ff0 ("sched/cache: Handle moving single tasks to/from their preferred LLC") Closes: https://lore.kernel.org/lkml/20260827135000.735138-1-zhanxusheng@xiaomi.com/ Reported-by: Zhan Xusheng Suggested-by: Chen Yu Signed-off-by: Tim Chen Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Kayra Cizmeci Cc: # v7.2.x Link: https://patch.msgid.link/06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com --- drivers/hid/hid-input-test.c | 85 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 drivers/hid/hid-input-test.c (limited to 'drivers/hid/hid-input-test.c') diff --git a/drivers/hid/hid-input-test.c b/drivers/hid/hid-input-test.c new file mode 100644 index 000000000..c92008daf --- /dev/null +++ b/drivers/hid/hid-input-test.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * HID to Linux Input mapping + * + * Copyright (c) 2022 José Expósito + */ + +#include + +static void hid_test_input_update_battery_charge_status(struct kunit *test) +{ + struct hid_battery *bat; + bool handled; + + bat = kunit_kzalloc(test, sizeof(*bat), GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bat); + + handled = hidinput_update_battery_charge_status(bat, HID_DG_HEIGHT, 0); + KUNIT_EXPECT_FALSE(test, handled); + KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_UNKNOWN); + + handled = hidinput_update_battery_charge_status(bat, HID_BAT_CHARGING, 0); + KUNIT_EXPECT_TRUE(test, handled); + KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_DISCHARGING); + + handled = hidinput_update_battery_charge_status(bat, HID_BAT_CHARGING, 1); + KUNIT_EXPECT_TRUE(test, handled); + KUNIT_EXPECT_EQ(test, bat->charge_status, POWER_SUPPLY_STATUS_CHARGING); +} + +static void hid_test_input_get_battery_property(struct kunit *test) +{ + struct power_supply *psy; + struct hid_battery *bat; + struct hid_device *dev; + union power_supply_propval val; + int ret; + + dev = kunit_kzalloc(test, sizeof(*dev), GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev); + + bat = kunit_kzalloc(test, sizeof(*bat), GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bat); + bat->dev = dev; + bat->avoid_query = true; + + psy = kunit_kzalloc(test, sizeof(*psy), GFP_KERNEL); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, psy); + psy->drv_data = bat; + + bat->status = HID_BATTERY_UNKNOWN; + bat->charge_status = POWER_SUPPLY_STATUS_CHARGING; + ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_UNKNOWN); + + bat->status = HID_BATTERY_REPORTED; + bat->charge_status = POWER_SUPPLY_STATUS_CHARGING; + ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_CHARGING); + + bat->status = HID_BATTERY_REPORTED; + bat->charge_status = POWER_SUPPLY_STATUS_DISCHARGING; + ret = hidinput_get_battery_property(psy, POWER_SUPPLY_PROP_STATUS, &val); + KUNIT_EXPECT_EQ(test, ret, 0); + KUNIT_EXPECT_EQ(test, val.intval, POWER_SUPPLY_STATUS_DISCHARGING); +} + +static struct kunit_case hid_input_tests[] = { + KUNIT_CASE(hid_test_input_update_battery_charge_status), + KUNIT_CASE(hid_test_input_get_battery_property), + { } +}; + +static struct kunit_suite hid_input_test_suite = { + .name = "hid_input", + .test_cases = hid_input_tests, +}; + +kunit_test_suite(hid_input_test_suite); + +MODULE_DESCRIPTION("HID input KUnit tests"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("José Expósito "); -- cgit v1.3.1