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, 146 insertions, 0 deletions

diff --git a/drivers/phy/rockchip/Kconfig b/drivers/phy/rockchip/Kconfig
new file mode 100644
index 000000000..14698571b
--- /dev/null
+++ b/drivers/phy/rockchip/Kconfig
@@ -0,0 +1,146 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Rockchip platforms
+#
+config PHY_ROCKCHIP_DP
+	tristate "Rockchip Display Port PHY Driver"
+	depends on ARCH_ROCKCHIP && OF
+	select GENERIC_PHY
+	help
+	  Enable this to support the Rockchip Display Port PHY.
+
+config PHY_ROCKCHIP_DPHY_RX0
+	tristate "Rockchip MIPI Synopsys DPHY RX0 driver"
+	depends on ARCH_ROCKCHIP || COMPILE_TEST
+	select GENERIC_PHY_MIPI_DPHY
+	select GENERIC_PHY
+	help
+	  Enable this to support the Rockchip MIPI Synopsys DPHY RX0
+	  associated to the Rockchip ISP module present in RK3399 SoCs.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called phy-rockchip-dphy-rx0.
+
+config PHY_ROCKCHIP_EMMC
+	tristate "Rockchip EMMC PHY Driver"
+	depends on ARCH_ROCKCHIP && OF
+	select GENERIC_PHY
+	help
+	  Enable this to support the Rockchip EMMC PHY.
+
+config PHY_ROCKCHIP_INNO_HDMI
+	tristate "Rockchip INNO HDMI PHY Driver"
+	depends on (ARCH_ROCKCHIP || COMPILE_TEST) && OF
+	depends on COMMON_CLK
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support the Rockchip Innosilicon HDMI PHY.
+
+config PHY_ROCKCHIP_INNO_USB2
+	tristate "Rockchip INNO USB2PHY Driver"
+	depends on (ARCH_ROCKCHIP || COMPILE_TEST) && OF
+	depends on COMMON_CLK
+	depends on EXTCON
+	depends on USB_SUPPORT
+	select GENERIC_PHY
+	select USB_COMMON
+	help
+	  Support for Rockchip USB2.0 PHY with Innosilicon IP block.
+
+config PHY_ROCKCHIP_INNO_CSIDPHY
+	tristate "Rockchip Innosilicon MIPI CSI PHY driver"
+	depends on (ARCH_ROCKCHIP || COMPILE_TEST) && OF
+	select GENERIC_PHY
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Enable this to support the Rockchip MIPI CSI PHY with
+	  Innosilicon IP block.
+
+config PHY_ROCKCHIP_INNO_DSIDPHY
+	tristate "Rockchip Innosilicon MIPI/LVDS/TTL PHY driver"
+	depends on (ARCH_ROCKCHIP || COMPILE_TEST) && OF
+	select GENERIC_PHY
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Enable this to support the Rockchip MIPI/LVDS/TTL PHY with
+	  Innosilicon IP block.
+
+config PHY_ROCKCHIP_NANENG_COMBO_PHY
+	tristate "Rockchip NANENG COMBO PHY Driver"
+	depends on ARCH_ROCKCHIP && OF
+	select GENERIC_PHY
+	help
+	  Enable this to support the Rockchip PCIe/USB3.0/SATA/QSGMII
+	  combo PHY with NaNeng IP block.
+
+config PHY_ROCKCHIP_PCIE
+	tristate "Rockchip PCIe PHY Driver"
+	depends on (ARCH_ROCKCHIP && OF) || COMPILE_TEST
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	select MFD_SYSCON
+	help
+	  Enable this to support the Rockchip PCIe PHY.
+
+config PHY_ROCKCHIP_SAMSUNG_DCPHY
+	tristate "Rockchip Samsung MIPI DCPHY driver"
+	depends on (ARCH_ROCKCHIP || COMPILE_TEST)
+	select GENERIC_PHY
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Enable this to support the Rockchip MIPI DCPHY with
+	  Samsung IP block.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called phy-rockchip-samsung-dcphy
+
+config PHY_ROCKCHIP_SAMSUNG_HDPTX
+	tristate "Rockchip Samsung HDMI/eDP Combo PHY driver"
+	depends on (ARCH_ROCKCHIP || COMPILE_TEST) && OF
+	depends on COMMON_CLK
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	select MFD_SYSCON
+	select RATIONAL
+	help
+	  Enable this to support the Rockchip HDMI/eDP Combo PHY
+	  with Samsung IP block.
+
+config PHY_ROCKCHIP_SNPS_PCIE3
+	tristate "Rockchip Snps PCIe3 PHY Driver"
+	depends on (ARCH_ROCKCHIP && OF) || COMPILE_TEST
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	select MFD_SYSCON
+	help
+	  Enable this to support the Rockchip snps PCIe3 PHY.
+
+config PHY_ROCKCHIP_TYPEC
+	tristate "Rockchip TYPEC PHY Driver"
+	depends on OF && (ARCH_ROCKCHIP || COMPILE_TEST)
+	select EXTCON
+	select GENERIC_PHY
+	select RESET_CONTROLLER
+	help
+	  Enable this to support the Rockchip USB TYPEC PHY.
+
+config PHY_ROCKCHIP_USB
+	tristate "Rockchip USB2 PHY Driver"
+	depends on ARCH_ROCKCHIP && OF
+	select GENERIC_PHY
+	help
+	  Enable this to support the Rockchip USB 2.0 PHY.
+
+config PHY_ROCKCHIP_USBDP
+	tristate "Rockchip USBDP COMBO PHY Driver"
+	depends on ARCH_ROCKCHIP && OF
+	depends on TYPEC
+	select GENERIC_PHY
+	select USB_COMMON
+	help
+	  Enable this to support the Rockchip USB3.0/DP combo PHY with
+	  Samsung IP block. This is required for USB3 support on RK3588.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called phy-rockchip-usbdp