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, 73 insertions, 0 deletions

diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
new file mode 100644
index 000000000..60bb7baf8
--- /dev/null
+++ b/drivers/input/keyboard/Makefile
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the input core drivers.
+#
+
+# Each configuration option enables a list of files.
+
+obj-$(CONFIG_KEYBOARD_ADC)		+= adc-keys.o
+obj-$(CONFIG_KEYBOARD_ADP5520)		+= adp5520-keys.o
+obj-$(CONFIG_KEYBOARD_ADP5585)		+= adp5585-keys.o
+obj-$(CONFIG_KEYBOARD_ADP5588)		+= adp5588-keys.o
+obj-$(CONFIG_KEYBOARD_AMIGA)		+= amikbd.o
+obj-$(CONFIG_KEYBOARD_APPLESPI)		+= applespi.o
+obj-$(CONFIG_KEYBOARD_ATARI)		+= atakbd.o
+obj-$(CONFIG_KEYBOARD_ATKBD)		+= atkbd.o
+obj-$(CONFIG_KEYBOARD_BCM)		+= bcm-keypad.o
+obj-$(CONFIG_KEYBOARD_CAP11XX)		+= cap11xx.o
+obj-$(CONFIG_KEYBOARD_CHARLIEPLEX)	+= charlieplex_keypad.o
+obj-$(CONFIG_KEYBOARD_CLPS711X)		+= clps711x-keypad.o
+obj-$(CONFIG_KEYBOARD_CROS_EC)		+= cros_ec_keyb.o
+obj-$(CONFIG_KEYBOARD_CYPRESS_SF)	+= cypress-sf.o
+obj-$(CONFIG_KEYBOARD_DLINK_DIR685)	+= dlink-dir685-touchkeys.o
+obj-$(CONFIG_KEYBOARD_EP93XX)		+= ep93xx_keypad.o
+obj-$(CONFIG_KEYBOARD_GOLDFISH_EVENTS)	+= goldfish_events.o
+obj-$(CONFIG_KEYBOARD_GPIO)		+= gpio_keys.o
+obj-$(CONFIG_KEYBOARD_GPIO_POLLED)	+= gpio_keys_polled.o
+obj-$(CONFIG_KEYBOARD_TCA8418)		+= tca8418_keypad.o
+obj-$(CONFIG_KEYBOARD_HIL)		+= hil_kbd.o
+obj-$(CONFIG_KEYBOARD_HIL_OLD)		+= hilkbd.o
+obj-$(CONFIG_KEYBOARD_IPAQ_MICRO)	+= ipaq-micro-keys.o
+obj-$(CONFIG_KEYBOARD_IQS62X)		+= iqs62x-keys.o
+obj-$(CONFIG_KEYBOARD_IMX)		+= imx_keypad.o
+obj-$(CONFIG_KEYBOARD_IMX_SC_KEY)	+= imx_sc_key.o
+obj-$(CONFIG_KEYBOARD_IMX_BBM_SCMI)	+= imx-sm-bbm-key.o
+obj-$(CONFIG_KEYBOARD_HP6XX)		+= jornada680_kbd.o
+obj-$(CONFIG_KEYBOARD_HP7XX)		+= jornada720_kbd.o
+obj-$(CONFIG_KEYBOARD_LKKBD)		+= lkkbd.o
+obj-$(CONFIG_KEYBOARD_LM8323)		+= lm8323.o
+obj-$(CONFIG_KEYBOARD_LM8333)		+= lm8333.o
+obj-$(CONFIG_KEYBOARD_LOCOMO)		+= locomokbd.o
+obj-$(CONFIG_KEYBOARD_LPC32XX)		+= lpc32xx-keys.o
+obj-$(CONFIG_KEYBOARD_MAPLE)		+= maple_keyb.o
+obj-$(CONFIG_KEYBOARD_MATRIX)		+= matrix_keypad.o
+obj-$(CONFIG_KEYBOARD_MAX7359)		+= max7359_keypad.o
+obj-$(CONFIG_KEYBOARD_MAX7360)		+= max7360-keypad.o
+obj-$(CONFIG_KEYBOARD_MPR121)		+= mpr121_touchkey.o
+obj-$(CONFIG_KEYBOARD_MT6779)		+= mt6779-keypad.o
+obj-$(CONFIG_KEYBOARD_MTK_PMIC) 	+= mtk-pmic-keys.o
+obj-$(CONFIG_KEYBOARD_NEWTON)		+= newtonkbd.o
+obj-$(CONFIG_KEYBOARD_NSPIRE)		+= nspire-keypad.o
+obj-$(CONFIG_KEYBOARD_OMAP)		+= omap-keypad.o
+obj-$(CONFIG_KEYBOARD_OMAP4)		+= omap4-keypad.o
+obj-$(CONFIG_KEYBOARD_OPENCORES)	+= opencores-kbd.o
+obj-$(CONFIG_KEYBOARD_PINEPHONE)	+= pinephone-keyboard.o
+obj-$(CONFIG_KEYBOARD_PMIC8XXX)		+= pmic8xxx-keypad.o
+obj-$(CONFIG_KEYBOARD_PXA27x)		+= pxa27x_keypad.o
+obj-$(CONFIG_KEYBOARD_QT1050)           += qt1050.o
+obj-$(CONFIG_KEYBOARD_QT1070)           += qt1070.o
+obj-$(CONFIG_KEYBOARD_QT2160)		+= qt2160.o
+obj-$(CONFIG_KEYBOARD_SAMSUNG)		+= samsung-keypad.o
+obj-$(CONFIG_KEYBOARD_SH_KEYSC)		+= sh_keysc.o
+obj-$(CONFIG_KEYBOARD_SNVS_PWRKEY)	+= snvs_pwrkey.o
+obj-$(CONFIG_KEYBOARD_SPEAR)		+= spear-keyboard.o
+obj-$(CONFIG_KEYBOARD_STMPE)		+= stmpe-keypad.o
+obj-$(CONFIG_KEYBOARD_STOWAWAY)		+= stowaway.o
+obj-$(CONFIG_KEYBOARD_ST_KEYSCAN)	+= st-keyscan.o
+obj-$(CONFIG_KEYBOARD_SUN4I_LRADC)	+= sun4i-lradc-keys.o
+obj-$(CONFIG_KEYBOARD_SUNKBD)		+= sunkbd.o
+obj-$(CONFIG_KEYBOARD_TC3589X)		+= tc3589x-keypad.o
+obj-$(CONFIG_KEYBOARD_TEGRA)		+= tegra-kbc.o
+obj-$(CONFIG_KEYBOARD_TM2_TOUCHKEY)	+= tm2-touchkey.o
+obj-$(CONFIG_KEYBOARD_TWL4030)		+= twl4030_keypad.o
+obj-$(CONFIG_KEYBOARD_XTKBD)		+= xtkbd.o