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, 327 insertions, 0 deletions

diff --git a/drivers/pinctrl/mediatek/Kconfig b/drivers/pinctrl/mediatek/Kconfig
new file mode 100644
index 000000000..30ef3dc5d
--- /dev/null
+++ b/drivers/pinctrl/mediatek/Kconfig
@@ -0,0 +1,327 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "MediaTek pinctrl drivers"
+	depends on ARCH_MEDIATEK || RALINK || COMPILE_TEST
+
+config EINT_MTK
+	tristate "MediaTek External Interrupt Support"
+	depends on PINCTRL_MTK || PINCTRL_MTK_MOORE || PINCTRL_MTK_PARIS || COMPILE_TEST
+	select GPIOLIB
+	select IRQ_DOMAIN
+	default y if PINCTRL_MTK || PINCTRL_MTK_MOORE
+	default PINCTRL_MTK_PARIS
+
+config PINCTRL_MTK
+	tristate
+	depends on OF
+	select PINMUX
+	select GENERIC_PINCONF
+	select GPIOLIB
+	select EINT_MTK
+
+config PINCTRL_MTK_V2
+	tristate
+
+config PINCTRL_MTK_MTMIPS
+	tristate
+	depends on RALINK
+	select PINMUX
+	select GENERIC_PINCONF
+
+config PINCTRL_MTK_MOORE
+	tristate
+	depends on OF
+	select GENERIC_PINCONF
+	select GENERIC_PINCTRL_GROUPS
+	select GENERIC_PINMUX_FUNCTIONS
+	select GPIOLIB
+	select EINT_MTK
+	select PINCTRL_MTK_V2
+
+config PINCTRL_MTK_PARIS
+	tristate
+	depends on OF
+	select PINMUX
+	select GENERIC_PINCONF
+	select GPIOLIB
+	select EINT_MTK
+	select PINCTRL_MTK_V2
+
+# For MIPS SoCs
+config PINCTRL_MT7620
+	tristate "MediaTek MT7620 pin control"
+	depends on SOC_MT7620 || COMPILE_TEST
+	depends on RALINK
+	default SOC_MT7620
+	select PINCTRL_MTK_MTMIPS
+
+config PINCTRL_MT7621
+	tristate "MediaTek MT7621 pin control"
+	depends on SOC_MT7621 || COMPILE_TEST
+	depends on RALINK
+	default SOC_MT7621
+	select PINCTRL_MTK_MTMIPS
+
+config PINCTRL_MT76X8
+	tristate "MediaTek MT76X8 pin control"
+	depends on SOC_MT7620 || COMPILE_TEST
+	depends on RALINK
+	default SOC_MT7620
+	select PINCTRL_MTK_MTMIPS
+
+config PINCTRL_RT2880
+	tristate "Ralink RT2880 pin control"
+	depends on SOC_RT288X || COMPILE_TEST
+	depends on RALINK
+	default SOC_RT288X
+	select PINCTRL_MTK_MTMIPS
+
+config PINCTRL_RT305X
+	tristate "Ralink RT305X pin control"
+	depends on SOC_RT305X || COMPILE_TEST
+	depends on RALINK
+	default SOC_RT305X
+	select PINCTRL_MTK_MTMIPS
+
+config PINCTRL_RT3883
+	tristate "Ralink RT3883 pin control"
+	depends on SOC_RT3883 || COMPILE_TEST
+	depends on RALINK
+	default SOC_RT3883
+	select PINCTRL_MTK_MTMIPS
+
+# For ARMv7 SoCs
+config PINCTRL_MT2701
+	tristate "MediaTek MT2701 pin control"
+	depends on MACH_MT7623 || MACH_MT2701 || COMPILE_TEST
+	depends on OF
+	default MACH_MT2701
+	select PINCTRL_MTK
+
+config PINCTRL_MT7623
+	tristate "MediaTek MT7623 pin control with generic binding"
+	depends on MACH_MT7623 || COMPILE_TEST
+	depends on OF
+	default MACH_MT7623
+	select PINCTRL_MTK_MOORE
+
+config PINCTRL_MT7629
+	tristate "MediaTek MT7629 pin control"
+	depends on MACH_MT7629 || COMPILE_TEST
+	depends on OF
+	default MACH_MT7629
+	select PINCTRL_MTK_MOORE
+
+config PINCTRL_MT8135
+	tristate "MediaTek MT8135 pin control"
+	depends on MACH_MT8135 || COMPILE_TEST
+	depends on OF
+	default MACH_MT8135
+	select PINCTRL_MTK
+
+config PINCTRL_MT8127
+	tristate "MediaTek MT8127 pin control"
+	depends on MACH_MT8127 || COMPILE_TEST
+	depends on OF
+	default MACH_MT8127
+	select PINCTRL_MTK
+
+# For ARMv8 SoCs
+config PINCTRL_MT2712
+	tristate "MediaTek MT2712 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK
+
+config PINCTRL_MT6765
+	tristate "MediaTek MT6765 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+
+config PINCTRL_MT6779
+	tristate "MediaTek MT6779 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+	help
+	  Say yes here to support pin controller and gpio driver
+	  on MediaTek MT6779 SoC.
+	  In MTK platform, we support virtual gpio and use it to
+	  map specific eint which doesn't have real gpio pin.
+
+config PINCTRL_MT6795
+	tristate "MediaTek MT6795 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+
+config PINCTRL_MT6797
+	tristate "MediaTek MT6797 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+
+config PINCTRL_MT6858
+	tristate "MediaTek MT6858 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+	help
+	  Say yes here to support pin controller and gpio driver
+	  on the MediaTek MT6858 SoC.
+
+config PINCTRL_MT6878
+	tristate "MediaTek MT6878 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+	help
+	  Say yes here to support pin controller and gpio driver
+	  on the MediaTek MT6878 SoC.
+
+config PINCTRL_MT6893
+	tristate "MediaTek Dimensity MT6893 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+	help
+	  Say yes here to support pin controller and gpio driver
+	  on the MediaTek Dimensity 1200 MT6893 Smartphone SoC.
+
+config PINCTRL_MT7622
+	tristate "MediaTek MT7622 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_MOORE
+
+config PINCTRL_MT7981
+	tristate "MediaTek MT7981 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_MOORE
+
+config PINCTRL_MT7986
+	tristate "MediaTek MT7986 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_MOORE
+
+config PINCTRL_MT7988
+	tristate "Mediatek MT7988 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_MOORE
+
+config PINCTRL_MT8167
+	tristate "MediaTek MT8167 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK
+
+config PINCTRL_MT8173
+	tristate "MediaTek MT8173 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK
+
+config PINCTRL_MT8183
+	tristate "MediaTek MT8183 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+
+config PINCTRL_MT8186
+	tristate "MediaTek MT8186 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+
+config PINCTRL_MT8188
+	tristate "MediaTek MT8188 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+	help
+	  Say yes here to support pin controller and gpio driver
+	  on MediaTek MT8188 SoC.
+	  In MTK platform, we support virtual gpio and use it to
+	  map specific eint which doesn't have real gpio pin.
+
+config PINCTRL_MT8189
+        tristate "MediaTek MT8189 pin control"
+        depends on OF
+        depends on ARM64 || COMPILE_TEST
+        default ARM64 && ARCH_MEDIATEK
+        select PINCTRL_MTK_PARIS
+        help
+          Say yes here to support pin controller and gpio driver
+          on MediaTek MT8189 SoC.
+          In MTK platform, we support virtual gpio and use it to
+          map specific eint which doesn't have real gpio pin.
+
+config PINCTRL_MT8192
+	tristate "MediaTek MT8192 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+
+config PINCTRL_MT8195
+	tristate "MediaTek MT8195 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+
+config PINCTRL_MT8196
+	tristate "MediaTek MT8196 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK_PARIS
+	help
+	  Say yes here to support pin controller and gpio driver
+	  on MediaTek MT8196 SoC.
+	  In MTK platform, we support virtual gpio and use it to
+	  map specific eint which doesn't have real gpio pin.
+
+config PINCTRL_MT8365
+	tristate "MediaTek MT8365 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK
+
+config PINCTRL_MT8516
+	tristate "MediaTek MT8516 pin control"
+	depends on OF
+	depends on ARM64 || COMPILE_TEST
+	default ARM64 && ARCH_MEDIATEK
+	select PINCTRL_MTK
+
+# For PMIC
+config PINCTRL_MT6397
+	tristate "MediaTek MT6397 pin control"
+	depends on MFD_MT6397 || COMPILE_TEST
+	depends on OF
+	default MFD_MT6397
+	select PINCTRL_MTK
+
+endmenu