sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling buggrafted

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 <zhanxusheng@xiaomi.com>
Suggested-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kayra Cizmeci <kayracizmeci@gmail.com>
Cc: <stable@kernel.org> # v7.2.x
Link: https://patch.msgid.link/06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com

1 files changed, 66 insertions, 0 deletions

diff --git a/drivers/macintosh/Makefile b/drivers/macintosh/Makefile
new file mode 100644
index 000000000..712edcb3e
--- /dev/null
+++ b/drivers/macintosh/Makefile
@@ -0,0 +1,66 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Macintosh-specific device drivers.
+#
+
+# Each configuration option enables a list of files.
+
+obj-$(CONFIG_PPC_PMAC)		+= macio_asic.o macio_sysfs.o
+
+obj-$(CONFIG_PMAC_MEDIABAY)	+= mediabay.o
+obj-$(CONFIG_MAC_EMUMOUSEBTN)	+= mac_hid.o
+obj-$(CONFIG_INPUT_ADBHID)	+= adbhid.o
+obj-$(CONFIG_ANSLCD)		+= ans-lcd.o
+
+obj-$(CONFIG_ADB_PMU)		+= via-pmu.o
+obj-$(CONFIG_ADB_PMU_EVENT)	+= via-pmu-event.o
+obj-$(CONFIG_ADB_PMU_LED)	+= via-pmu-led.o
+obj-$(CONFIG_PMAC_BACKLIGHT)	+= via-pmu-backlight.o
+obj-$(CONFIG_ADB_CUDA)		+= via-cuda.o
+obj-$(CONFIG_PMAC_APM_EMU)	+= apm_emu.o
+obj-$(CONFIG_PMAC_SMU)		+= smu.o
+
+obj-$(CONFIG_ADB)		+= adb.o
+obj-$(CONFIG_ADB_MACII)		+= via-macii.o
+obj-$(CONFIG_ADB_IOP)		+= adb-iop.o
+obj-$(CONFIG_ADB_MACIO)		+= macio-adb.o
+
+obj-$(CONFIG_THERM_WINDTUNNEL)	+= therm_windtunnel.o
+obj-$(CONFIG_THERM_ADT746X)	+= therm_adt746x.o
+obj-$(CONFIG_WINDFARM)	        += windfarm_core.o
+obj-$(CONFIG_WINDFARM_PM72)     += windfarm_fcu_controls.o \
+				   windfarm_ad7417_sensor.o \
+				   windfarm_lm75_sensor.o \
+				   windfarm_max6690_sensor.o \
+				   windfarm_pid.o \
+				   windfarm_cpufreq_clamp.o \
+				   windfarm_pm72.o
+obj-$(CONFIG_WINDFARM_RM31)     += windfarm_fcu_controls.o \
+				   windfarm_ad7417_sensor.o \
+				   windfarm_lm75_sensor.o \
+				   windfarm_lm87_sensor.o \
+				   windfarm_max6690_sensor.o \
+				   windfarm_pid.o \
+				   windfarm_cpufreq_clamp.o \
+				   windfarm_rm31.o
+obj-$(CONFIG_WINDFARM_PM81)     += windfarm_smu_controls.o \
+				   windfarm_smu_sensors.o \
+				   windfarm_lm75_sensor.o windfarm_pid.o \
+				   windfarm_cpufreq_clamp.o windfarm_pm81.o
+obj-$(CONFIG_WINDFARM_PM91)     += windfarm_smu_controls.o \
+				   windfarm_smu_sensors.o \
+				   windfarm_lm75_sensor.o windfarm_pid.o \
+				   windfarm_cpufreq_clamp.o windfarm_pm91.o
+obj-$(CONFIG_WINDFARM_PM112)	+= windfarm_pm112.o windfarm_smu_sat.o \
+				   windfarm_smu_controls.o \
+				   windfarm_smu_sensors.o \
+				   windfarm_max6690_sensor.o \
+				   windfarm_lm75_sensor.o windfarm_pid.o
+obj-$(CONFIG_WINDFARM_PM121)	+= windfarm_pm121.o windfarm_smu_sat.o \
+				   windfarm_smu_controls.o \
+				   windfarm_smu_sensors.o \
+				   windfarm_max6690_sensor.o \
+				   windfarm_lm75_sensor.o windfarm_pid.o
+obj-$(CONFIG_PMAC_RACKMETER)	+= rack-meter.o
+
+obj-$(CONFIG_SENSORS_AMS)	+= ams/